Embracing superdiversity and multilingualism in English as a medium of instruction in STEM classrooms: a participatory action research

The global expansion of English as a Medium of Instruction (EMI) in STEM education creates significant pedagogical challenges when implemented in linguistically superdiverse classrooms of the Global South. This participatory action research addresses the critical gap between EMI policy and practice by co-developing responsive pedagogical strategies with six STEM teachers in a South African township school, a context where English Across the Curriculum operates amidst learners speaking twelve or more home languages. Framed by translanguaging theory, the study employed three iterative cycles of collaborative planning, classroom observations, reflective journals, and focus groups. Findings reveal a transformative shift in teachers’ professional identities from passive policy implementers to critical literacy mediators who strategically deploy scaffolded translanguaging and multimodal resources for epistemological access in STEM. While persistent structural constraints, particularly monolingual high-stakes assessments, continue to temper practice, the study demonstrates that sustained collaborative inquiry empowers teachers as agents of change. Beyond South Africa, this research offers transferable insights for EMI implementation in superdiverse settings globally, advocating for context-responsive pedagogies that reconcile English-medium instruction with multilingual classroom realities.