Drawing upon the Triadic Reciprocity Framework, this longitudinal qualitative multiple-case study examined how three Hong Kong secondary English as a second language (ESL) teachers exercised their teacher agency to take control of their teaching and professional development. More specifically, the study aimed at exploring how teachers' intentions and actions for the establishment of their professional identity were afforded and constrained by their workplaces. Findings reveal that these ESL teachers exercised different degrees of proactive, reactive, and passive agency. The four properties of human agency, i.e., intentionality, forethought, self-reactiveness, and self-reflectiveness, influenced the teachers' proactive, reactive, and passive agency when they responded to personal, behavioral, and environmental determinants. The findings shed light on a three-layered Triadic Reciprocity framework on teacher agency and contributes to a systematic and comprehensive discussion about the various internal and external factors that might exert influences on agency of early career teachers. This study offers pedagogical implications for school teachers, school leaders, and policy makers in Hong Kong and beyond.
