This paper investigates how instances of language use can serve as analytic anchors for insight into interactional development over time. I present a usage-based, longitudinal study of multi-turn sequences underlying telephone openings in order to specify if and to whom "language learning" may be relevantly ascribed. Two successive analyses of the same data segment are conducted, once in terms of distributed cognition and a second time in terms of individual cognition. Both analyses produce different results. Ultimately, this paper specifies opportunities and constraints in usage-based studies focusing on interactional development over time in second language learners. The results call for more cross-disciplinary research that encompasses both the social and the cognitive.