Nan Yao, Lei Yang, Aynur Kesen Mutlu
ABSTRACT Grounded in social constructivist and affective learning perspectives, this study addressed a key research gap concerning how teacher interpersonal behaviours and emotional factors jointly influence Mongolian English as a Foreign Language (EFL) learners' engagement in technology‐mediated classrooms. Despite extensive research on teacher–student interactions and learner affect in other regions, Mongolian trilingual learners in the Inner Mongolia Autonomous Region of China remain underrepresented in empirical inquiry. To bridge this gap, the present study examined the relationships among teacher interpersonal behaviours, communication apprehension, self‐efficacy, willingness to communicate and academic engagement. Participants were 588 Mongolian trilingual undergraduates selected through purposive sampling. Data were collected via five validated scales, and analyses were conducted using SPSS Version 27 for descriptive, correlational and regression analyses, and AMOS Version 24 for structural equation modelling (SEM). Results revealed strong positive correlations among the main constructs, with SEM indicating that teacher interpersonal behaviours ( β = 0.42, p < 0.001) positively predicted self‐efficacy, willingness to communicate and engagement, while communication apprehension ( β = −0.36, p < 0.001) negatively affected these outcomes. The model explained 64% of the variance in academic engagement, supporting the hypothesised relationships. These findings highlight the critical role of supportive teacher–student relationships and the need to address emotional barriers in digital learning environments. The study contributes theoretically by extending engagement models to trilingual, technology‐enhanced EFL contexts and practically by offering pedagogical recommendations for fostering affective support and reducing communication apprehension to optimise learner participation.