Minority language, Mandarin, and English in contact: trilingual translanguaging and teacher agency in Northwest China’s multi-ethnic secondary schools

In Northwest China’s multi-ethnic borderlands, Uyghur, Tibetan, Kazakh, and other minoritised communities navigate linguistic ecologies in which heritage languages, Mandarin, and English coexist within secondary education. Drawing on translanguaging theory and the ecological model of teacher agency, this study examines teachers’ beliefs, practices, and agency in implementing trilingual translanguaging pedagogy where students’ linguistic repertoires intersect with national language policy and monolingual examination requirements. A sequential explanatory mixed-methods design surveyed 350 teachers across Xinjiang, Gansu, and Qinghai, followed by 20 classroom observations and 25 semi-structured interviews. Results reveal high endorsement of translanguaging beliefs (M = 4.17) but moderate implementation in practice (M = 3.32), with minoritised teachers scoring significantly higher than Han counterparts (p < .001, d = 2.10). Structural equation modelling indicates that beliefs are strongly associated with practices (β = .65), mediated by policy pressure, resource availability, and ethnic diversity support, collectively explaining 45% of the variance. Qualitative findings document teachers’ micro-agency through cultural bridging despite Gaokao monolingualism. Joint display integration reveals that the belief–practice gap is structurally rather than attitudinally driven. Implications call for culturally sustaining professional development and trilingual assessment accommodations, transferable to multilingual minority education in global Indigenous and minoritised language communities.