Abstract
Content and Language Integrated Learning (CLIL) is promoted globally to enhance subject knowledge and language learning, yet professional development (PD) often overlooks teachers’ cultural insights and pedagogical expertise, creating a gap between policy and classroom realities. In Kazakhstan, top-down CLIL reforms risk marginalising teachers’ voices and reproducing one-size-fits-all approaches. This paper reports on a 45-hour PD programme for biology teachers designed around the pedagogical nexus and Systemic Functional Linguistics (SFL) to examine how culturally and linguistically responsive PD can contribute to CLIL practice. Using a qualitative case study design, we analysed journals, interviews, peer reflections, and lesson documents from 11 biology teachers. Findings show three interrelated shifts: teachers developed a new understanding of the language of science, reimagined their pedagogy to integrate language with content, and adapted CLIL practice through translanguaging, post-Soviet traditions, and cultural values of teaching. These shifts highlight how pedagogical habitus shaped teachers’ engagement with PD. The study contributes a context-sensitive CLIL PD model that foregrounds teacher expertise and demonstrates how locally grounded initiatives can strengthen reform in Kazakhstan and other multilingual settings.