This article provides an empirically based perspective on the contribution of conversation analysis (CA) and sociocultural theory to our understanding of learners' second language (L2) practices within what we call a strong socio-interactionist perspective. It explores the interactive (re)configuration of tasks in French second language classrooms. Stressing that learning is situated in learners' social, and therefore profoundly interactional, practices, we investigate how tasks are not only accomplished but also collaboratively (re)organized by learners and teachers, leading to various configurations of classroom talk and structuring specific opportunities for learning. The analysis of L2 classroom interactions at basic and advanced levels shows how the teacher's instructions are reflexively redefined within courses of action and how thereby the learner's emerging language competence is related to other (interactional, institutional, sociocultural) competencies. Discussing the results in the light of recent analyses of the indexical and grounded dimensions of everyday and experimental tasks allows us to broaden our understanding of competence and situated cognition in language learning.