This study investigates the Initiation-Response-Feedback (IRF) interaction pattern in teacher-student discourse during English language learning in Class XII ULP at SMKN 2 Kuningan. Utilizing a qualitative approach through classroom discourse analysis, the research applies the IRF model proposed by Sinclair and Coulthard (1975) and the variation framework by Nassaji and Wells (2000). The data were collected from field-recorded classroom videos, which were then transcribed, coded, and categorized into four IRF variations: Standard, Extended, Reversed, and Chain. Analysis revealed that the Standard IRF dominated teacher-student interactions, especially during managerial and material modes, with Extended and Chain IRF appearing in more reflective and collaborative phases. Reversed IRF, though less frequent, signaled student autonomy in initiating communication. Furthermore, the study mapped these patterns across four classroom discourse modes managerial, materials, skills and systems, and classroom context—using Walsh’s (2001) framework. The findings show that each IRF type correlates with different discourse modes and pedagogical purposes. In particular, Chain IRF was common in classroom context mode, promoting dialogic learning, while Standard IRF was prevalent in skills mode, ensuring language accuracy. This study offers a nuanced view of how teacher-student interactions unfold in a vocational classroom and how IRF structures support learning engagement. The integration of discourse mode analysis deepens understanding of interaction dynamics and instructional intent. The results highlight the importance of strategic variation in classroom communication to foster participation and learning outcomes in EFL contexts.