Abstract

This study deepens the understanding of multilingual education by exploring the experiences of university students who are in the process of developing trilingual proficiency, with a particular focus on Chinese and English. Set within active learning environments utilising digital technologies and English as a Medium of Instruction (EMI), it adopted a sequential explanatory mixed-method design using data from diverse sources, including questionnaires, learning outcomes, and interviews. Using the convenience sampling method, 95 undergraduates from various academic disciplines participated. The quantitative data were examined using descriptive and inferential statistics, while the qualitative interview data were examined using deductive thematic analysis adopting an interpretivist paradigm. Findings indicate that Thai university students showed higher self-efficacy in English than Chinese. Although male students reported slightly higher levels, these differences were not statistically significant. Self-efficacy positively correlated with English outcomes but not with Chinese, highlighting a complex link between self-efficacy and language learning. Exploratory Factor Analyses highlighted distinct factors underpinning self-efficacy in English and Chinese among Thai university students, with both languages showing factors related to proficiency, communication, and skill mastery, accounting for a substantial variance. Qualitative findings revealed varied student perceptions of their language proficiency and the differences between English and Chinese.