Understanding <scp>TESOL</scp> Non‐University‐Based Teacher Educators' Expertise and Its Development: An Activity Theory Perspective

Abstract Informed by activity theory (AT), the present study explores the expertise of two Teaching English to Speakers of Other Languages (TESOL) non‐university‐based teacher educators (NUBTEs) in China and the factors that contribute to their expertise development. Despite the critical role TESOL NUBTEs play in bridging policy and practice for frontline TESOL teachers, limited research has examined their professional expertise, particularly through the lens of AT. This study addresses this gap by drawing on semi‐structured interviews, non‐participatory field observations, and relevant artifacts to identify TESOL NUBTEs' expertise across four dimensions: (1) a strong mission of supporting the professional growth of all TESOL teachers; (2) context‐responsive knowing about and for TESOL teacher education; (3) effective strategies for integrating TESOL theory and practice; (4) mature social–emotional competence to navigate and transform TESOL education within existing structures. The participants' expertise functioned and developed through their long‐term adaptive interaction with various factors within and across three activity systems: professional development activity system, policy‐related activity system, and learning activity system. The study proposes a context‐specific framework for TESOL NUBTEs' expertise and its development from an expanded AT perspective. It concludes with practical implications for TESOL NUBTEs on how to navigate their expertise development in this time of flux.