Developing professional capacity for Content Language Integrated Learning (CLIL) teaching in Vietnam: tensions and responses

Abstract In this paper, we report on an international collaborative project designed to address the professional development needs of Vietnamese teachers for the implementation of Content and Language Integrated Learning (CLIL). We collected data on a group of CLIL Vietnamese teachers and leaders through online interviews. Drawing on Cultural-Historical Activity Theory (CHAT), the paper illuminates how CLIL teachers, as the subject of the professional learning (PL) system, utilized tools to develop their capacity for CLIL teaching against the backdrop of various sociocultural factors that regulate this learning process. The analysis helped us to identify various challenges facing CLIL teachers’ PL. These challenges arose from an absence of an effective learning system mostly related to contextual obstacles and widespread misconceptions, even among the leaders and CLIL trainers, about the nature of CLIL. This study contributes suggestions to enhance the quality of PL for CLIL teachers, which is a pressing issue for the successful implementation of CLIL in the context of Vietnam and beyond.


Introduction
Content and Language Integrated Learning (CLIL) has been promoted as a pedagogical approach to enhance the learning and teaching of English and subject content in Europe.Many policy makers and other stakeholders (e.g.parents) believe that CLIL potentially 'equips every citizen with a knowledge of English and that it is also the way to transcend the perceived weaknesses of traditional foreign language teaching' (Dalton-Puffer 2011, p. 185).Driven by such beliefs, governments in the Asia-Pacific region have also been introducing CLIL into their educational systems from pre-primary level to tertiary level (Gilanyi et al. 2023).Countries implementing CLIL include Malaysia (Yassin et al. 2009), Indonesia (Adijaya 2023), Korea (Lee 2020), Thailand (Liu 2022), Taiwan (Yang 2015), and Vietnam (Nhan 2013), where English is not widely used beyond the classroom.These studies have documented that significant challenges need to be addressed by these educational systems to successfully implement CLIL programmes and ensure that students benefit from them.One of the most significant challenges relates to teachers and their readiness for CLIL teaching.
CLIL teaching, with its twofold foci on content and language learning outcomes, is no easy undertaking for teachers: CLIL is a dual-focused educational approach in which an additional language is used for the learning and teaching of both content and language.That is, in the teaching and learning process, there is a focus not only on content, and not only on language.Each is interwoven, even if the emphasis is greater on one or the other at a given time (Coyle et al. 2010, p. 1).
The complexity of CLIL teaching, as highlighted by Brüning and Purrmann (2014), stems from the fact that CLIL teachers are responsible for teaching both content and language in their lessons.Therefore, they are required to master not only the subject matter content and the language associated with the subject matter, but also how to make both comprehensible to students (Cammarata and Tedick 2012).Eurydice Report (2006) emphasizes the need for teachers to acquire both explicit knowledge in the areas of 'language competence and teaching and methodological skills, as well as a good knowledge of the non-language subject to be taught ' (p. 41) and the implicit knowledge that enables teachers to balance or synthesize language and content in their lesson planning and classroom practice.It is critical for the success of content and language learning how and what teachers teach is rethought (Coyle et al. 2010), as teachers play a key role in any educational change.
To make this happen, Coyle (2006) puts forward the 4Cs Framework, aiming to lay a methodological foundation for the design of CLIL lessons based on the four principles of Content, Cognition, Communication and Culture.Recognition of these principles allows CLIL to be implemented across contexts.CLIL teachers are expected to provide students not only with defined knowledge and skills within the curriculum, but also creative thinking, problem-solving and cognitive challenges (Coyle et al. 2010).
Despite the critical role that teachers play in successful CLIL implementation, there is an inadequate supply of teachers; CLIL teachers in most contexts lack confidence in undertaking CLIL lessons, language proficiency and are insufficiently equipped to teach CLIL lessons (Hu and Gao 2021;Lo 2020;Taylor 2022;Fielden Burns and Martínez Agudo 2023;Pun and Gao 2023).Pineda et al. (2022) echo the need for CLIL teachers to be provided with learning opportunities to develop their professional capacity for effective CLIL teaching in many contexts (e.g.Taiwan and Spain).Yet, CLIL teachers' professional development (PD) is one of the 'many grey areas when it comes to CLIL' (McDougald 2019, p.198) as previous research has paid limited attention to CLIL teachers' PD (Cammarata and O'Ceallaigh 2020).There is no standard CLIL teacher professional framework for teacher education and development in many contexts (Kewara and Prabjandee 2018).Even in Europe, where there is a long tradition of CLIL implementation, insufficient professional training and development of CLIL teachers has become a significant barrier to successful CLIL implementation, because the demand for CLIL teachers is higher than the supply (Villabona and Cenoz 2022) and the current CLIL teacher training programmes do not 'fit the bill' (Pérez Cañado 2018;Pérez Agustín 2019).Coyle et al. (2010) 'highlight that without serious attention being paid to implementing strategies for training the professional workforce, which include longer-term plans for skilling multilingual teachers, then quality CLIL is not sustainable ' (pp. 161-162).
Researchers have recently begun to pay more attention to CLIL teachers' professional learning (PL) in a variety of contexts.In Thailand, Prabjandee and Kewara (2023) identified that teachers experienced different stages of identity development in the process of learning to teach CLIL, including 'accidental (stepping into CLIL: an accidental journey), responsible(conforming to new roles), experimental (the trial and errors method), investment (endless professional development), transformative (CLIL changes identity), and perseverance (implementing CLIL against collegial resistance' (p.775).It is paramount to see how teachers experience their journey of learning to teach CLIL in other contexts.However, most relevant have focused on the main topics, such as how to teach CLIL teachers (Azparren Legarre 2022), what PD programmes are offered, and what their outcomes are (e.g.Banegas 2020;McDougald and Pissarello 2020;Azparren Legarre 2022).These studies tend to focus on a top-down approach which regards teachers as receivers in the PD process, pays little attention to their voice in their own learning, and fails to address issues of localization.Scholars often study single-event formats, such as attending courses and seminars (Banegas 2020;Polyakova and O'Callaghan 2023).This simplistic view of CLIL teachers' PD does not address the complexity and dynamics of CLIL teachers' learning across contexts.It can also be contended that CLIL teachers' PD is undertheorized in these studies.Most research only explored CLIL teachers' professional learning as an individual learning activity from teachers.For this reason, more research from a wider range of contexts, such as Vietnam, is needed to further understand CLIL teachers' PL.

CLIL policy and practice in Vietnam
CLIL has taken a particular form in Vietnam.CLIL has long been recognized in various French bilingual programmes since Vietnam became a member of Agence de Coopération Culturelle et Technique.However, the promotion of CLIL programmes in the English language has become a focus of language education reforms since 2008 (Nhan 2013).While CLIL is supported as a form of bilingual education for all students in Europe (Coyle et al. 2010), in Vietnam CLIL is only targeted at some groups as a special programme for those schools and institutions that have sufficient conditions for the implementation of the programme.'Developing the Gifted High School System, Period 2010 to 2020' (Decision No. 959/QD-TTg) (Government of Vietnam 2010) recommended that natural science subjects should be taught entirely in English in pilot programmes in schools for gifted children.English is increasingly being used as the medium of instruction (MoI) at all stages of the Vietnamese education system (Le et al. 2019).At the secondary education level, English as medium of instruction (EMI) has been used in about 20 schools for gifted children since 2013, with one to two lessons per week in mathematics and science subjects (Nguyen and Hai 2018).These programmes are restricted to high schools for gifted children (Nhan 2013).In the Vietnamese context, CLIL tends to be language focused.This soft CLIL model reflects the current practice of CLIL in Vietnam, which can be interpreted as 'a foreign language enrichment measure packaged into content teaching' (Dalton-Puffer and Smit 2013, p. 546).
The government recognizes the importance of syllabus design, material development, and CLIL teacher development in implementing CLIL (Government of Vietnam 2010).CLIL teachers, in addition to fulfilling all of the knowledge and skill requirements for Vietnamese school teachers, must meet the requirement for proficiency in the target language.They must be 'at least two levels higher as stated in Vietnam's European Teacher Competence Framework (ETCF), in comparison to the student's expected outcome' (Government of Vietnam 2014, p. 2).For example, as high school students are expected to have a B1 level, high school teachers must have at least a C1 level of proficiency in the target language (ETCF).Teachers of mathematics, physics, chemistry, biology, and computer science attend short or long-term training courses, either domestically or overseas, about teaching subject matter in English.As part of teacher preparation, the government has also stated the need for the development of CLIL material for the teaching of mathematics, physics, chemistry, biology, and computer science in English (Government of Vietnam 2010).
Despite these legal stipulations and the increasing implementation of CLIL in both public and private schools in Vietnam, research in has shown that CLIL implementation in the country is facing several challenges (Pham and Unaldi 2022;Nguyen 2019;Nguyen et al. 2023;Phan 2021), the biggest of which are the scarcity of CLIL-qualified teachers (Nhan 2013) and the lack of understating of CLIL-based pedagogical approaches (Nguyen 2016;Thai et al. 2020).There is thus a pressing need for systematic, ongoing in-service PD for CLIL teachers in Vietnam, but little is known about CLIL teacher PD in this context.Among the limited studies on this topic, Pham and Unaldi (2022) stress the need to equip CLIL teachers with learning opportunities that are relevant to their contexts and the ability to take control of their own PL.Given that CLIL teacher development is in an 'embryonic' stage (Pérez Cañado 2018), there is a pressing need for researchers to explore teachers' preparation for CLIL teaching in Vietnam.Therefore, our study addresses the following research question: How do teachers develop their professional capacity for CLIL teaching in Vietnam?

Teachers' professional development through the lens of Cultural Historical Activity Theory
To address the research question, we adopt Cultural-Historical Activity Theory (CHAT) as our framework for understanding the dynamics and complexity of CLIL teachers' PL (Engeström 2001).CHAT builds on Vygotskian sociocultural theory, which conceptualizes human mental functioning (in this case CLIL teacher PL) as taking place within socioculturally, historically and socially mediated activity systems.To understand CLIL teachers' PL, we adopt Engeström's (2001) 'collective activity system' concept (p.134), which is 'an effort to place mediation in its cultural context' (Cole and Gajdamaschko 2007, p. 206).In this system, the three-component model of Subject, Object and Mediating Artefact (Vygotsky 1978) enables researchers to explore 'not only the mediated nature of the participant-object relation but also the mediated nature of all relations between pairs of entities' (Roth and Tobin 2002, p. 114).Therefore, CHAT offers a useful framework for investigating teacher PL, especially in settings where CLIL teacher learning is regulated by various factors such as the materials and facilities they use (tools), who they interact with (community), the policies and norms they follow (rules), and the responsibilities they take (division of labour).
In addition, the CHAT system also views CLIL teachers not as 'products' of the learning system but as 'agents' who contribute to developing the system as a whole.Consequently, the CHAT framework can inform the development of CLIL teacher training programmes that are based on the participants' input.As Engeström (2001) states, 'the individual could no longer be understood without his or her cultural means; the society could no longer be understood without the agency of individuals who use and produce artifacts' (p.134).These assumptions match the paradigm of multilingual research, providing us with guidance on how multilingual resources within international collaborative research teams can be effectively deployed to enable Vietnamese CLIL teachers to articulate their experiences and voices in the process (Holmes et al. 2022).
In this paper, we focus on the second generation of CHAT (Figure 1) due to its alignment with our purpose of understanding human activity (i.e.PL for teachers) within a complex social context (i.e.PL for CLIL teachers).It allows for a 'focus at the level of individual teacher practices but also at the broader organisation level' (Murphy and Rodriguez-Manzanares 2008, p. 444).In this learning system, the CLIL teachers are the subjects, who participate in the setting with their own objects, understood as the 'true motive' of the learning system (Leont′ev 1978, p. 62).To achieve these objects, CLIL teachers must see different signs and use different tools: both physical tools such as training materials, feedback forms, and coursebooks, and psychological tools such as language, beliefs, zone of proximal development (ZPD) and reflective conversations.The way in which CLIL teachers learn is regulated by socio-cultural factors that are conditioned into the system, including community, rules, and division of labour.In this project, the community is primarily composed of PL programme organisers, school leaders, colleagues, and students, the rules are both the national and school policies and norms that regulate CLIL teachers' practice and PL, and the division of labour within the community includes both the division of tasks, power and status between members (Engeström and Sannino 2010).All of these sociocultural factors regulate the process by which the teachers use mediating artefacts to achieve the object.These components of the second generation of CHAT shape the conceptualization, data collection, and analysis in the present study.

The study
This study is an international collaboration between Vietnam's Ministry of Education and Training (MOET) and an Australian university.The study involved 42 CLIL teachers and 10 managers/leaders who were selected using purposive sampling.Purposive sampling is the 'deliberate selection of specific individuals, events, or settings' to ensure that rich information and in-depth understanding are obtained during the data collection process (Liamputtong 2013).The managers/leaders were people who were in charge of the CLIL programs in schools and centres across Vietnam.The teachers who agreed to take part in this study were teaching CLIL at primary and/or secondary levels across Vietnam.In Vietnam, both language teachers and subject teachers can teach CLIL, and we selected participants from both groups; some had specific training in language teaching, while others had been trained in subjects such as science and mathematics.Of the 42 teachers who participated in this study, only five held a degree in CLIL education and the remaining were formally trained in either English language education or a specialist subject.Most participant teachers in the study became CLIL teachers after completing formal university study in a specific subject area (either in English or in mathematics, physics or chemistry, etc.) and then received 'on the job' training, typically through short training courses.They teach CILL at different types of schools (publica and private) across Vietnam.

Data generation and analysis
We used the researching multilingually paradigm to guide us on how multilingual resources within this international collaborative research team could be effectively deployed to enable Vietnamese CLIL teachers to articulate their experiences and voices in the PL process (Holmes et al. 2022).Data for this study were gathered via online interviews with the participants.As a team of multicultural researchers, we conducted this study with an RM-ly (Researching Multilingually) dimension in mind, which is reflected in our process of preparing data generation instruments for participant recruitment, generating data, analysing data, and finally writing up the report.The RM-ly research framework highlights the use of more than one language in the research process.It calls for researchers to make conscious efforts to make reflective decisions about linguistic and cultural issues related to the conduct of their research (Andrews et al. 2019).
When designing our interview protocol, we needed to make several decisions about language choice.We agreed that the interviews should be conducted in Vietnamese, the participants' mother tongue, as the use of L1 is the best way to facilitate comprehension and nuanced expression (Clark et al. 2017).As CLIL is still a foreign concept in the Vietnamese educational context, the term needed to be translated into Vietnamese.Instead of directly translating CLIL into Vietnamese, we decided to use the term popularly used to refer to CLIL programmes in Vietnam: dạy tiếng Anh tích hợp ('integrated English teaching').Although this Vietnamese term does not convey the exact meaning of the CLIL concept, it ensured that the participants correctly understood the programmes we were discussing and enabled us to evaluate their knowledge of CLIL as a pedagogical approach.Our interview questions were devised by consulting the broad literature on CLIL in the English, Chinese and Vietnamese languages, the CHAT framework, and policy documents in Vietnamese.
The RM-ly framework also points out the spatiality dimension of research practice, and how different research spaces impact researchers' decision-making (Holmes et al. 2022).The conduct of our research was bound by both the Australian requirements for the ethical conduct of human research and the Vietnamese research culture.While the former requires a somewhat 'hands-off ' approach to participant recruitment, the latter relies more on personal relationships.Without trust gained through personal introductions, it would be hard to recruit research participants in Vietnam.
Each participant was interviewed by the Vietnamese members of our research team for one hour via Zoom.The semi-structured interviews were audio-recorded and transcribed verbatim by our research assistants, who were familiar with transcription conventions.Online meetings, which were held due to the COVID-19 pandemic, presented a new research space that required different relationship-building techniques to make participants feel comfortable before they could open up for our interview questions.In the interviews, we asked questions about the participants' educational and professional backgrounds, their experience of becoming CLIL teachers, their conceptualization of CLIL teaching, their current situation in terms of CLIL practices, and their PD needs.
With regard to data analysis, a constant comparative method (Strauss and Corbin 2008) was employed for code identification, thematic analysis and the identification of findings.The next stage aimed to identify the activity systems, following the comprehensive eightstep procedure suggested by Yamagata-Lynch (2010).The qualitative data were then organized according to the activity system analysis.This process created flexibility in terms of allowing themes to develop from the research questions, the theoretical framework, and the research participants' narratives.Although the transcripts were in Vietnamese, we decided to use English for the codes and themes to facilitate research collaboration and publication in English.All three researchers who knew the language were involved in translating the quotes, coding the data, and identifying the themes.

Findings
The findings are structured according to the themes identified from the different components of the CLIL teacher PL activity in the light of CHAT (Figure 2).As will be presented, CLIL teachers, the subjects of the PL system, are self-motivated individuals who have a real motive to improve their CLIL teaching competences (the object).To work towards the realization of their learning motives, the CLIL teachers utilized a range of mediating tools which encompassed both physical tools (e.g.teaching materials, or the curriculum) and conceptual tools (e.g.lesson observation).The findings presented in this section focus on the subjects' backgrounds and their interaction with different sociocultural factors when they engaged with the PL system.

The subjects' background: Limited CLIL pedagogy in initial teacher education and language competence
The interviews with the teachers and leaders reveal an urgent need for more quality CLIL pedagogy training.Even amongst the small number of teachers who had received formal CLIL teacher education, there was a consensus that their training route did not differ much from that of the conventional subject teacher education program, except that the language of delivery was primarily in English: Frankly speaking, we were taught the same subjects as those taking the maths teacher education programme were; just that the subjects were taught in English.(Mai Anh, CLIL teacher) As a matter of fact, the CLIL teacher education programme provides scant knowledge of CLIL pedagogy.The mere translation of the teaching content into English reflects an 'old-product-in-new-packaging' approach, indicating a lack of focus on CLIL methods in these programmes and thus the need for further training: In fact, at university, we only studied like the regular subject matter students, but the teachers teach in English during the teaching process.
[…] By nature, we would be teaching physics so the lecturers put lot of emphasis on physics teaching.From time to time, they would mention some tips to teach science in English, but it was not on a frequent basis.(Thanh, CLIL teacher) It is evident from the above excerpt that the participants had not received adequate preparation for CLIL teaching in their initial teacher education programmes, particularly with reference to the Vietnamese context.Son, a CLIL/Maths teacher, stated: In fact, as far as I understand, our lecturers just aimed at teaching us the knowledge in English.In terms of pedagogy, it would be similar everywhere.So let's say, what would be considered progressive education in Vietnam would have similar requirements in the rest of world.So instead of drawing new knowledge, they would take the existing knowledge from the internet or international coursebooks for us to learn.
For other CLIL teachers, the trajectory seems to have been that they originally majored in either English teaching or a specialist subject (e.g.mathematics, physics, chemistry, etc.) and then converted to teaching CLIL following some training in the form of short courses.The motivations behind the transition might be diverse, with some being selected by their school leaders as part of the requirements of the national CLIL scheme and some volunteering to participate in these programmes.However, one common feature shared by the teachers was an urgent need to supplement a lack of the appropriate knowledge and competences for CLIL teaching.Specifically, most existing subject teachers who had not achieved the required English level had to take intensive language and short CLIL training courses, both organized by the Ministry of Education and Training (MOET) and considered compulsory requirements for their transitions.Commenting on the language courses, Thy Nguyen (CLIL teacher) noted: Luckily the Department of Education has organized two language courses for us.For the first course, we are supposed to achieve B1 level in line with the CEFR framework, which I have already passed.In the second summer the target is to achieve B2 level and at the moment I am revising for the B2 exam.
The PD journey for most English teachers seemed to be distinct from Thy Nguyen's experience.Unlike their counterparts with specialist subject majors, the English teachers normally converted to CLIL due to their own wish to explore new knowledge and/or change their career paths.Hanh Nguyen, for instance, described her transition to teaching CLIL/ Maths as follows: I am the type who enjoys exploring, and if I don't know about something, I would be curious to learn about it.So it was the time when my centre introduced CLIL, and I was keen to learn how different it was from other English programmes.And when I started teaching, I realized the teaching methods were different from the general English that I had been teaching.(Hanh Nguyen, CLIL teacher) The journey for many, therefore, seems to have involved taking a self-initiated training programme in the subject in order to meet the entry requirements.Due to their initial lack of content knowledge, the majority of these teachers opted to teach at the primary level, where the level of content knowledge required is supposedly lower than it is at the secondary level.After joining the CLIL team, these teachers, as with other in-service CLIL members, would have to undertake CLIL PD courses organized by the Ministry of Education and Training (MOET) or by the organizations where they work.
Given the pathways to becoming a CLIL teacher in Vietnam, teachers have slightly different learning targets, focusing primarily on either subject matter content or language competency, depending on their primary initial teacher education (ITE) background.All participants, however, emphasized the need for training in CLIL pedagogy.This, as Nhan (a Department of Education and Training officer) explained, is due to the fact that 'CLIL methodology is not the combination of content and language teaching, but it is such a new and different area which they have never been trained before' .In addition, the majority of teachers, particularly those originally educated in a subject other than English, were not confident about their English language competence.This is understandable, as low English proficiency levels amongst teachers have been a perpetual issue in the Vietnamese educational context (e.g.Nguyen 2015; Le and Le 2022).Even among teachers who had achieved the language proficiency level (B2) required by the MOET, there have been concerns about their ability to teach content using English as the language of instruction.Anh Tuyet, for instance, commented: To be honest, my English level is now quite good, but to teach entirely in English, I don't feel that I am up to it.(Anh Tuyet, CLIL programme manager/teacher) The teacher's unease with using English in teaching subject content despite her satisfactory English level might derive from the fact that effective communication in CLIL teaching requires not only Basic Interpersonal Communication Skills (BICS) but also Cognitive Academic Language Proficiency (CALP) (Anderson 2011).This aligns with findings from a previous Vietnamese study that highlighted participants' difficulty in giving instructions, explaining concepts, and answering questions in English (Nguyen 2016).

CLIL Professional learning: an ineffective use of tools
As highlighted above, all CLIL teachers in Vietnam are entitled to take training courses prior to and during their professional careers.These courses are either organized by the MOET in collaboration with commissioned organizations such as MB (pseudonym) or by the institutions where they work, and thus they are diverse in nature.The training organized by the MOET can range from three-day intensive courses to more prolonged courses that last two months.For CLIL teachers who work for established organizations, there appears to be more sustained training that takes place throughout their teaching time in the form of lesson observations.From a CHAT perspective, lesson observation could be considered a psychological tool (Vygotsky 1978) utilized to help teachers achieve their PL goals.The findings, however, point to the ineffective use of this tool due to both time constraints and perceptions of the meaningfulness of certain activities.In terms of training duration, there seems to be a consensus among CLIL teachers that three days are not enough for them to acquire significant knowledge for their teaching.Nguyet, for instance, commented: Just three days of training is not sufficient to learn anything.On the first day, we received the materials that contained the procedure, criteria and preparations needed to teach CLIL.Then we practised teaching right away -I mean, after learning the theories, each group would prepare a short 15-minute lesson to teach.To me, this is like 'watching flowers while riding on horseback' .Honestly, I am not confident enough to teach CLIL.I may know the concepts in English, but to explain or teach in English is beyond my capability.(Nguyet, CLIL teacher) The metaphorical expression 'watching flowers while riding on a horseback' that Nguyet adopted has its origin in a Chinese proverb (走马观花) which is mainly used to criticize a cursory working style used by people who thus fail to gain insight into the nature of their work.By referring to the training programme as 'watching flowers while riding on a horseback' , not only did Nguyet show her dissatisfaction with the brevity of the training programme, but she also implied that such training has limited potential to help CLIL teachers develop vital knowledge for teaching.This is in line with what other teachers identified as the 'distance' between CLIL training and real-life teaching.Sang Nguyen put it as follows: Mostly the training focused on the new textbooks, and then we would have demo lessons where one teacher taught and another gave feedback […] In general each lesson should be 40 minutes, but the demo lesson lasted 20 minutes.Honestly the demo lesson did not say much about real CLIL teaching, just 40%.Demo means you teach, and other teachers act as your students, so it is different from teaching your real students.(Sang Nguyen, CLIL teacher) In a similar line, Trang Nguyen raised concerns about the applicability of trainers' observation of demo lessons to her own teaching, as 'what they taught could not apply to my students […].Their students were those whom they had taught for a long time, and lived in cities, so they were more competent than mine' .In this vein, a deviation from CLIL teachers' real-life teaching contexts seems to have limited the effectiveness of lesson observation as a tool in CLIL teachers' PL.More seriously, there seems to be some misunderstanding about the focus of CLIL education among CLIL mentors, as was reflected in Trang Nguyen's comment: […] the teaching method in general.We learnt how to develop a lesson plan -things like what should be included in a maths lesson.In fact, the procedure is a bit different from teaching English, so for instance, when I teach a formula or a new concept, what I should do to make it understandable to students.My trainers always say that when I teach maths in English, I should not over-emphasize maths knowledge because students are assumed to already have all that knowledge.90% of students do already know, so the teacher is supposed to teach English concepts of maths.The actual calculations, you know, things like addition, subtraction, multiplication or division, the students have already learnt.(Trang Nguyen, CLIL teacher) The above excerpt suggests a tendency for trainers to understand CLIL teaching as simply re-teaching content knowledge in English.This seemingly reflects a misconception about the nature of CLIL, over-simplifying the technique into the mere teaching of a subject in a different language.This misunderstanding might threaten the ultimate goal of CLIL, which is a dual focus on both language and content (Pérez Cañado 2018).
Textbooks and supplementary teaching resources are another tool popularly used in CLIL teachers' PL.In this regard, there seem to exist two contrasting trends.The dominant trend was the adoption of the translated versions of MOET-published textbooks: We use the bilingual textbooks approved by the MOET.They are actually a series of textbooks in Vietnamese that have incorporated English translations…so it is like there is one paragraph in Vietnamese and one in English (Chung, CLIL teacher).
This approach mirrors an oversimplification of the cultural aspects of CLIL education, as translated textbooks may focus primarily on the culture of the Vietnamese language without incorporating intercultural perspectives, thus inhibiting students' understanding of cultural diversity and distorting the global nature of CLIL (Viebrock 2015).
The other trend involved importing a set of textbooks from abroad, which is typical for schools that run the duo-diploma programme (allowing students to graduate with a MOETaccredited diploma and a foreign diploma such as a General Certificate of Secondary Education,(GCSE) and private centres.One issue with adopting foreign-imported textbooks, as Anh Tuyet (CLIL programme manager/teacher) identified, is the mismatch between the difficulty levels of the Vietnamese and the foreign programmes.For her, this gave rise to tension when mediating the teaching content: We currently use imported textbooks, but one problem is that the content is too easy compared with the Vietnamese curriculum and our students have already learnt all the content beforehand.But if we taught the Vietnamese programme in English, honestly, I would not be able to because the content would be too heavy, and we don't have sufficient resources.You know, if we had to translate the Vietnamese textbooks into English to teach, it would be terrible.(Anh Tuyet, CLIL programme manager/teacher) For a minority of teachers working for private organizations such as iMap (pseudonym) training tended to be more frequent, ranging from 3-4 days per series every 3-4 months.
What seemed to differentiate iMap training from other programmes was the fact that many of iMap's teaching staff were originally English teachers.Therefore, a significant part of their teacher PD programme involved strengthening teachers' content knowledge of the subject they taught: They wanted their teachers to have sound foundational knowledge of maths and science […] For instance, earlier this school year, our training programme focused on knowledge of maths and science and how to impart difficult maths and science knowledge to students in an easily understandable way.(Huong Nguyen, CLIL teacher) Alongside regular training, iMap made lesson observation and feedback a compulsory part of their teacher PD journey.On average, each teacher is required to 'observe at least six lessons' and to 'be observed frequently by their colleagues' (Phuong Lan).Unlike the demo lesson observations organized by the MOET, teachers at iMap are obliged to participate in real-life lessons, which seems to be a better response to their teaching needs.
When I first started teaching, I did not have experience at all, and there were challenges related to IT applications as well […] So in the beginning, we were observed almost every lesson by our academic coordinator.They would come to observe, to support and provide feedback for us to improve our teaching.(Trung, CLIL teacher) However, one problem with the iMap training programme, as Nga identified, was the fact that the teaching programme had been prepared for teachers in advance: If teachers rely on a pre-made programme, they cannot create their lesson in their own way and develop their own teaching style.As for the students, they may feel that the lessons are quite boring, because every teacher teaches in the same way.(Nga, CLIL teacher) Since the lesson plans and teaching materials have already been prepared, there is little space for CLIL teachers to design lessons in their own way; this threatens to turn teachers into 'technician, consumer, receiver, transmitter, and implementer of other people's knowledge' rather than 'knowers, thinkers, leaders and change agents' (Lawson et al. 2015, p. 393).In this way, the overly rigid nature of the programme and the misuse of lesson plans as a tool may hamper rather than support teachers' PD.

Interaction with the wider school community: an absence of a collaborative work culture
It was evident from the dataset that despite being a prioritized government scheme, CLIL still maintains an insignificant position in schools.This was evidenced by the lack of support for CLIL implementation from school leaders and students.In most schools, CLIL was only an elective subject, and CLIL teachers hardly received any formal training or support.Dung, for instance, commented: In terms of professional development, honestly, I wasn't engaged in any training courses or model lesson observations.Everything that I have brought into my class was based on what I have learnt as a pre-service maths teacher plus how I convert these materials into English.Basically, I wasn't trained in a methodical way in this area.(Dung, CLIL teacher) Teachers being left alone in their journey to become CLIL practitioners, alongside the absence of appropriate teaching materials, curriculum, and policy, indicates that schools contest the government's top-down policies.The consequence of this seems to have been that many CLIL teachers feel marginalized or lack the commitment to become part of the teaching community of the school.Tu (CLIL teacher) further added: I was sent to teach two CLIL periods per week.I don't have any connection with the school and the other teachers.When I finish my lesson, I just leave.
As the extract above shows, the participants felt isolated from other colleagues in the school.This isolation negatively impacts CLIL teachers' engagement with the school community, discouraging them from collaborating with other teachers.Trang (CLIL teacher) complained about being deprived of opportunities to observe their colleagues' teaching practices: I want to observe and have a conversation with maths and science teachers, but we have little opportunity to do it.
These findings show that at the school level, there seems to be little shared space for collaborative interaction, experience sharing, discussions about teaching practice, or reflection on teaching, which have been widely acknowledged as conducive to learning in the context of CLIL teachers' PD (e.g.Rui et al. 2022).Such a less collaborative work culture seems to discourage teachers from supporting and/or collaborating with others within their immediate communities of practice in order to develop their professional competences.Instead, they concentrated on improving their own learning through self-generated PL activity such as self-study, which is discussed in the section below.

Professional learning strategies: Self-initiated learning to teach CLIL
As Engeström (2001) puts it, 'the individual could no longer be understood without his or her cultural means; the society could no longer be understood without the agency of individuals who use and produce artifacts' (p.134).The use of CHAT enabled us to focus on what the participants attempted to achieve when addressing the tensions involved in their PD.We have identified that the participants not only undertook individual efforts to develop their CLIL teaching capacity, but also organized collective efforts.
As highlighted above, most participants did not receive adequate professional preparation prior to beginning CLIL teaching and struggled to access quality PD opportunities relevant to CLIL teaching.Consequently, most had to work out ways to improve their knowledge and skills; this included self-study, taking paid PD courses, and engaging in peer observation.As CLIL is a new disciplinary area in the Vietnamese context, the participants had to spend a lot of time learning from those sources they could access to develop pedagogical knowledge and skills for their teaching.
I can self-study by looking for learning materials like courses and apps in English.(Mai Anh) In addition to self-study, the participants attempted to join a variety of free and paid PD courses provided by the Department of Education or commercial publishers.It must be noted that the financial costs involved in these PD courses have been a huge obstacle, discouraging teachers from joining these courses: I took part in several online courses organized by Cambridge University Press.As they are paid courses, there would be some I would love to join but am unable to.(Thanh CLIL teacher) It might surprise readers that the participants would pay out of their own pockets to undertake PD courses because of a policy decision initiated by the government.While it is possible that these participants were motivated to seek career advances in light of the government's push for CLIL teaching, their acts also reflect the desperate need that they felt had to be addressed by implementing CLIL as a new pedagogical approach.Constrained by policymakers' limited financial investment in their PD, many participants decided to come together to organize supportive communities of practice where they observe each other's lessons, provide feedback on how each other's teaching can be improved, discuss common challenges in teaching, and share their experiences of CLIL teaching.The participants expressed their deep appreciation of the learning opportunities created by these supportive communities of practice: We have a group where we can share our problems, so issues like 'I was teaching this lesson yesterday, and the model was not working […]' and everyone could exchange and discuss how to solve that problem.(Hong Nguyen, CLIL teacher) As documented in the interviews, the participants also learnt from each other about pedagogical ideas that could be implemented in CLIL teaching, and also learnt to develop pedagogical strategies such as motivating students to learn through observation.In addition, some participants also reached out to colleagues beyond their immediate professional settings and asked for help from international support groups on social media such as Facebook.Thanh (CLIL teacher), for instance, joined an Indian group on Facebook, which allowed him to explore CLIL approaches and trends in the wider world: I mainly engage in the physics group and I must tell you, I am not even aware of how many subscribers there are.But whenever there is a post that asks a question, there are so many comments, so many responses to that question.
Through engaging with CLIL practitioners in other contexts, the participants developed understandings of how CLIL could be implemented and how they might deliver CLIL teaching in Vietnam.It was through such collaborative, supportive exchanges that the participants began to develop pedagogical understandings and strategies for CLIL teaching.
Another strategy which was highly valued but rarely used in schools was the discussion of CLIL issues among teachers and the observation of other teachers.Some of the CLIL teacher participants stated that one benefit of peer observation was that they could apply their peers' ideas in their own classroom.They wanted to have more opportunities for classroom observation and discussions with other teachers within their schools.Team teaching with subject teachers was also recommended as a practical strategy to support CLIL teaching: Observing the foreign and subject teachers' lessons helps me a lot.They know how to motivate students.I do it by myself.My school does not have any programme to support this.(Van, CLIL teacher) The CLIL teachers' PL activities thus remain largely limited to the level of the individual teacher and are only randomly expanded to other teachers by the individual seeking out collaborative learning opportunities.This underscores the need to create a community where CLIL teachers are provided with opportunities for collective reflection and collaboration.

Discussion
This is probably one of the few studies on CLIL teachers' PL efforts to meet the needs of CLIL teaching in the context of Vietnam.In this study, we examined and interpreted the participants' experiences, focusing on the challenges that they experienced and the responses they adopted to develop their professional capacity.As captured by the study, the participants' PL is not an individual activity but a socially mediated collective activity, which needs support and engagement from different stakeholders.
The study identified the lack of qualified CLIL teachers as a serious challenge for the promotion and implementation of CLIL in Vietnam, resonating with findings in other contexts such as Thailand, Spain and Taiwan (Pérez Cañado 2018;Fielden Burns andMartínez Agudo 2023, McDougald 2019;Prabjandee and Kewara 2023).Teachers have limited knowledge of CLIL pedagogy, leading to tensions and contradictions when undertaking a dual focus on content and language in CLIL lessons.In alignment with Pham and Unaldi (2022), the findings confirm that Vietnamese CLIL teachers struggle to identify themselves as language-and content-integrated teachers.The findings further reveal that the trajectory of learning to become a CLIL teacher in Vietnam is mostly 'accidental' and 'experimental' (Prabjandee and Kewara 2023;p. 775).Like CLIL teachers in other contexts (Prabjandee and Kewara 2023), the participant teachers were placed in CLIL classes without preparation or proper training and had to manage and trial different teaching methods in their own classrooms.In response to the challenging task of CLIL teaching, they selfinitiated PL to develop their professional capacity.Nevertheless, all the available PL opportunities were ad hoc and accidental.Pineda et al. (2022) argue that 'each CLIL context has its own unique teacher profiles and the corresponding training needs ' (p. 11).The findings of the present study reveal that CLIL teachers, whether they identify as content teachers or language teachers, need PL opportunities to improve linguistic proficiency and develop pedagogical competence regardless of their educational background and teaching experience.The results also reflect the complexities surrounding pathways to become CLIL teachers and their learning needs as a result of the current shift in language education.
Using the CHAT framework, we have illuminated the tensions which can arise as CLIL teachers interact with the various sociocultural factors involved in the PL system.Most of these tensions were associated with the contextual characteristics pertaining to Vietnamese education and systemic misconceptions of the nature of CLIL.With CLIL teacher education being a fairly recent discipline, it is understandable that the main route to becoming a CLIL teacher in Vietnam is through 'converting' from being an in-service English or subject teacher; this necessitates the organization of PL courses to equip these teachers with the skills and knowledge they need as CLIL teachers.Even the minority of CLIL teachers who had a CLIL teacher education background needed further training due to the ineffective provision of CLIL-related pedagogical knowledge in their education.This, as the findings of our research highlight, is an 'old-product-in-new-packaging' approach, as the programme was merely a translation of the course content into English.With regard to the teachers engaged in the PL system, ineffective use of learning tools (e.g., training workshops, lesson observation and feedback) was recorded; this impeded CLIL teachers' realization of the PL object.Trainers' misunderstanding of the nature of CLIL, evidenced by their constant reminders to CLIL teachers not to 'over-emphasize maths knowledge, because students are assumed to have learnt all the knowledge' , might derive from the misalignment of the level of difficulty in subject content between the Vietnamese programme and programmes imported from abroad.However, this misconception seems to distort the true goal of CLIL due to its focus on merely re-teaching content using a second language of instruction.This finding highlights the fact the CLIL programmes in Vietnam tend to be more language-driven than content-driven, which points to the importance of reconceptualizing CLIL teaching and CLIL's professional learning in similar contexts.Effective PL programs should consider the need for having a shared goal of CLIL teaching practice, providing the teachers with effective PD strategies such as lesson observation and feedback, promoting a culture of collaboration, and empowering them with opportunities to pursue autonomy for PL.
Furthermore, the study indicates that resources are often insufficient for the development of context-sensitive CLIL pedagogies, allowing CLIL teachers to not only achieve the dual goal of teaching language and content but also to preserve the vitality of multi-national languages and cultures in the process.In light of Coyle's et al. (2010) 4Cs Framework, both selecting English translations of Vietnamese textbooks and adopting imported textbooks jeopardize the intercultural component considered critical in CLIL education (Czura 2017).Effective preparation of CLIL teachers should, therefore, equip them with the skills they need to adapt textbooks and materials in a way that enables both teachers and students to appreciate the diversity of languages and cultures within and across nations during the education process.Towards this, initial teacher education providers and continuous PD programmes need to both promote CLIL teachers' critical awareness of multilingual and multicultural resources and enhance their strategic use of these resources for effective CLIL teaching.This could be done through the promotion of culturally responsive pedagogy in CLIL instruction (Le Pichon et al. 2023), which would allow recognition and appreciation of students' diverse backgrounds, the integration of their lived experiences, and meaningful connections between their cultural identities and the content delivered to them.Such targeted CLIL pedagogies may also involve the use of translanguaging practices to teach the target language along with subject content knowledge considered appropriate to the students' level of readiness for learning and CLIL teachers' level of readiness for teaching.
Our study also revealed that the participants made their best efforts to seek opportunities for PL and establish self-initiated supportive networks for PD.This finding strongly supports the characterization of CLIL teachers as proactive learners (Prabjandee and Kewara 2023).The participants' commitment to developing their professional capacity for CLIL teaching enabled them to shape their PL trajectories and reduce the negative impacts of the ineffective top-down PL system imposed by the MOET.In this sense, the CLIL teachers became agents of change who set an example of how the PL activity system could be improved through collaborative practices such as peer lesson observation and discussion.In line with Kennedy's (2016) advocacy for a shift in PD based on a more 'nuanced understanding of what teachers do, what motivates them, and how they learn and grow' (p.974), it is advisable for schools to empower teachers to become change agents in their PL as well as to address issues of interest to teachers and not just issues imposed by other stakeholders (Hargreaves 1997).The findings also suggest that effective PL programmes need to provide sufficient opportunities for CLIL teachers to reflect on and collaborate with others (e.g.coordinators and other teachers).Through such collaborative exploration, CLIL teachers can expand their agency with regard to constructing and implementing context-sensitive pedagogical responses to the challenges of CLIL teaching.
Given the diverse perspectives on the knowledge base of CLIL teachers, it is critical to develop a core CLIL teacher competence framework (Marsh et al. 2012) as a mediating tool to prepare qualified CLIL teachers for CLIL implementation.Our recommendation strengthens the findings of several studies that champion the pressing need for sufficient specific CLIL methodological training and language development in existing undergraduate degrees and PD programmes (Pérez Cañado 2018).As it is in other contexts, it is critically important that key CLIL teacher competences be identified to frame the chief 'CLIL teacher training needs from multifaceted perspectives' (Pérez Cañado 2018, p.218).

Conclusion
The findings of this study raise critical issues which should be considered when supporting CLIL teachers' PL in the Vietnamese context and beyond and especially amid ongoing educational reform.CLIL teachers' PL is not an individual activity, but rather a collective endeavour.The findings of this study lead us to the conclusion that addressing the identified challenges requires tremendous effort not only from individual teachers and their schools, but also from educational systems.Reflecting on our findings, we make the following suggestions for CLIL teacher education and development programmes in Vietnam and similar contexts: 1.All stakeholders (teachers, school leaders, policy makers, and educational leaders) need to work together to provide sufficient resources (e.g.textbooks and materials) to support CLIL teaching and create a community of practice where CLIL teachers can learn from each other and collaborate with each other to enhance their teaching practice in their own contexts (Pham and Unaldi 2022).This will help reduce the tensions arising from the top-down PL system while empowering teachers to be active agents in their learning process.2. CLIL teacher professional development programmes should transcend beyond the mere focus on language and/or content.Instead, greater efforts are to be made to develop CLIL teachers' pedagogical content knowledge, embracing the multicultural and multilingual values reinforced in CLIL instruction (Bower et al. 2020).This can be achieved through the adoption of culturally responsive pedagogy in CLIL instruction (Le Pichon et al. 2023) that bring forth students' diverse backgrounds, prior knowledge and lived experience.3.There is a need to develop a contextually based CLIL teacher competence framework as a tool to inform and guide teachers towards effective CLIL teaching practice.This framework will help to mediate the structure and outcomes of CLIL teacher initial education and PL programmes.In addition, collaboration in developing the CLIL teacher competence framework will facilitate communications, which in turn help to eradicate misunderstandings about the nature of CLIL prevalent in the Vietnamese context and similar contexts.
As CLIL is a recent educational initiative in countries like Vietnam, it remains to be seen how its implementation will impact the learning and teaching of English in these contexts, and whether it will result in an improvement in students' English language proficiency and subject content knowledge.Reflecting on the application the RM-ly framework, we believe that RM-ly framework is essential to carrying out the research as it forms the philosophical stand of the research.As a team of CLIL researchers who have worked in the context of Vietnam, Hongkong, and Australia, we have constantly embraced all research members' reflexibility in all steps of conducting and writing up our research.Due to the multilingual nature of CLIL contexts and practices, the RM-ly framework guides us to problematise the research issues and adjust the research methodologies to meet the needs of conducting such a complex topic in a multilingual context .We are also much concerned about the extent to which the implementation of CLIL will disrupt the existing linguistic ecology as well as undermine the recognition of linguistic and cultural resources millions of students bring with to CLIL classrooms.Further research is needed to ensure that CLIL teachers draw on students' multilingual resources to develop effective CLIL practices for teaching the target language and subject content in contexts where multiple languages are used outside the classroom.

Disclosure statement
No potential conflict of interest was reported by the authors.