The development of college English teachers' pedagogical content knowledge (PCK): from General English to English for Academic Purposes

College English teachers' pedagogical content knowledge (PCK) is subject to change in the transition from the teaching of General English (GE) to that of English for Academic Purposes (EAP). Underpinned by Grossman's four-dimensional model of PCK, this study aims to investigate the trajectory of PCK development among college English teachers through the transition from GE to EAP in the Chinese context. Adopting a qualitative case study approach, multiple sources of data about three teachers were collected through semi-structured interviews, class observations, and teaching materials. Results show that teachers' conceptions of the purpose of teaching EAP, as opposed to GE, are fundamental to PCK development. The development of different PCK components was mainly attributed to a variety of informal learning activities, which are insufficient for well-balanced development. Additionally, the development of PCK was hindered by teachers' limited content knowledge. The findings have significant implications for effective college English teacher development in the transition from GE teaching to EAP teaching.