Conversation analysis (CA) has been used for interventionist purposes in different fields, such as medicine, mediation services, and speech and language therapy, but it has yet to be fully utilised in teacher education. In this report, I describe how CA is used in teacher supervision to intervene with the development of a student-teacher (ST) in a 7th grade English as a Second Language classroom over the course of an academic year. In particular, with a focus on three issues of elicitations (unpreparedness, lack of focus and unresponsiveness), I present interactional evidence in a before-and-after manner to highlight ST's growth in the three areas through repeated cycles of CA-based reflective analysis. Findings contribute to interventionist CA research as well as a growing body of work that uses CA in the classroom to examine the nuances of teaching.