Academic buoyancy in EFL learning: A mixed-methods study among Chinese private university students

English language learning in linguistically homogeneous contexts such as China remains a challenging process in which learners routinely face everyday academic setbacks. Drawing on the framework of Positive Psychology, this study examines academic buoyancy among 366 EFL undergraduates at a Chinese private university using an explanatory sequential mixed-methods design. Three research questions address students' perceptions of academic buoyancy, its association with English language achievement, and the external contextual factors that contribute to its development. Quantitative data were collected through a survey questionnaire; qualitative data were gathered through semi-structured interviews with five students. Results indicated that participants generally held positive perceptions of their academic buoyancy across four dimensions, with sustainability rated highest and regularity adaptation lowest. Hierarchical regression analysis, controlling for gender, age, and daily English study time, revealed that academic buoyancy was significantly and positively associated with English language achievement. Among the four dimensions, positive acceptance of academic life showed the strongest association with achievement. Thematic analysis of interview data identified two key external contributors to academic buoyancy: positive interactions with instructors and peers, and a supportive learning environment, with the dormitory emerging as a notable site of informal peer support. These findings suggest that academic buoyancy is meaningfully associated with language achievement in this context and is sustained through social and environmental conditions. The study implies that language educators should cultivate supportive learning environments and peer support systems, particularly in private university settings where informal learning networks may compensate for limited institutional resources.