Most conversation analysis (CA) studies of the initiation-response-feedback (IRF; Sinclair & Coulthard, 1975) sequence have focused on teacher actions in the feedback move. In this article, I use CA to analyze student initiatives (Waring, 2011) within an IRF sequence in one excerpt from a Chinese as a foreign language class. The excerpt features a teacher using an IRF sequence to engage her students in a sentence-based translation exercise. I demonstrate how a student initiates a sequence following the teacher's feedback move to make a negative assessment of the pragmatic soundness of the sentences, thus casting doubt on the teacher's epistemic authority. This initiating action and the subsequent interaction it generates bring contingency into the IRF sequence and create potential learning opportunities. As the teacher contends with the contingency, issues related to epistemic asymmetry and L1 and L2 identities are brought to the surface. Additionally, the potential opportunities to discuss the different pragmatic forces between "yao" in Chinese and "to want" in English when used in making requests are missed at multiple sequential junctures. Based on the analysis, I discuss teacher-student epistemic social relations within the IRF sequence and a methodological issue concerning the analysis of missed learning opportunities. I also offer reflection on how CA can be used for pedagogical intervention.