In the wake of globalisation and the widespread dominance of English, Southeast Asian countries have experienced significant shifts in their foreign language policies, prioritising English instruction over other languages. While numerous studies have explored teacher agency in response to educational change, understanding the motivations behind their actions warrants further attention. Amidst this evolving educational landscape in culturally nuanced contexts like Southeast Asia, unpacking the influence of Asian sociocultural values on how teachers exert agency during this transition could provide in-depth insights into teacher agency and their decision making. Employing a sociocultural approach and drawing on Bourdieu's theory of practice, this paper examines the sociocultural factors shaping the agency of 20 teachers in a Vietnamese university as they respond to a profound educational change-the transition from teaching modern foreign languages (e.g., French, Chinese, and Russian) to teaching English. Through teacher interviews with 20 transitioned teachers, supplemented by insights from interviews with two faculty and university leaders, the findings reveal the embodiment of Bourdieu's concepts of Habitus and Capital in Vietnamese adaptability, flexibility, family roles, responsibilities, and teachers' sense of collectivity as influential factors on teacher agency. Additionally, the hierarchical nature of change implementation, as reflected in leaders' orientations, organisational constraints, and administrative styles, viewed through the lens of Field and social networks, contributes to the intricate dynamics of the transition process. Understanding these findings is crucial for comprehending the factors that constrain and facilitate teachers' responses to change within the complex interplay of individual dispositions, societal structures, and power distribution within the educational sphere.
