This article explores the usage- and exemplar-based roots of second language (L2) negation construction learning. Based on two longitudinal case studies involving two adult L2 English learners and a corpus of 63 three-hour sessions of recorded classroom interactions, the study shows that L2 learning follows the predictions of usage-based models of language knowledge and acquisition, as the two participants' learning of English negation constructions is found to go from recurring expressions toward an increasingly schematic, dynamic inventory of linguistic resources. Furthermore, exploring the evolution of two negation patterns in ongoing discourse, I suggest that local usage and long-term learning are inseparable and call for further detailed investigations of how locally contextualized interactions influence L2 development.