Reconceptualizing English-medium instruction as policy enactment: teacher agency and multilingual practice in low-resource contexts

English-medium instruction (EMI) policies are often formulated through monolingual assumptions despite multilingual classroom realities. Although EMI research recognizes teachers as policy actors, less is known about how policy enactment, teacher agency, street-level discretion, and multilingual pedagogy interact in low-resource primary schools in sub-Saharan Africa. Drawing on policy enactment theory, ecological accounts of teacher agency, street-level bureaucracy, and language-policy scholarship on practiced and negotiated policy, this qualitative multiple-case study examined EMI enactment in three public primary schools in Malawi. Data comprised 20 semi-structured interviews with teachers, headteachers, and district education officials, 30 classroom observations, and 10 policy and school documents. Reflexive thematic analysis identified five conditions shaping enactment: material constraints, uneven access to English, teacher English proficiency, pedagogical preparation, and institutional ambiguity. Teachers responded through planned and responsive multilingual practices, including bilingual explanation, translanguaging, language alternation, scaffolding, and peer mediation. These practices preserved English as the authoritative language while making content accessible. The study conceptualizes EMI not as a fixed English-only model but as recursively negotiated policy-in-practice. Its contribution is to integrate insights on teacher policy-making and translanguaging into a context-sensitive model of EMI enactment in Malawian primary education, showing multilingual practices as mechanisms of street-level policy mediation under constraint.