This postscript discusses the contributions of the four articles in this issue to the field and positions them in relation to other studies in recent CA research on L2. The articles focus on the two arenas for L2 learning: the classroom and the lifeworld of learners. These arenas are widely different from each other and equally so within with respect to organization and participation frameworks and the social practices deployed; but the interactional problems that participants confront inside and outside of the classroom partially overlap. Learning and teaching objects (or 'learnables') are brought into being by the participants through their joint actions, at particular moments in the ongoing activity, be it in a classroom or a situation in the lifeworld. The four articles re-specify standard SLA concepts in interactional terms: attention and noticing (Kunitz, 2018, this issue), corrective feedback (Majlesi, 2018, this issue), negotiation of/for meaning (Eskildsen, 2018, this issue), and corrections and metalinguistic explanations (Theodórsdóttir, 2018, this issue). Their re-specification adds value to these concepts because it furnishes them with a publicly visible interactional grounding and shows in each case how linguistic items become objects for reflexive linguistic practices by the participants.