The goal of this course is to introduce students to a view regarding the syntax-pragmatics interface which takes into considerations insights from other linguistic frameworks that are dedicated to dealing with language in interaction (e.g., conversation analysis, interactional linguistics, etc.). This departs from traditional generative assumptions according to which the language of interaction is largely considered to be a matter of performance (rather than competence). However, work in conversation analysis has clearly demonstrated that a communicative competence underlies the human ability to talk to each other. We will explore aspects of this communicative competence that are arguably in the purview of grammatical knowledge. I will present and use a syntactic model (the interactional spine hypothesis, Wiltschko 2021) according to which the construction of common ground as well as the regulation of turn-taking is (in part) constrained by the syntactic spine. Broadening the domain of syntax in this way leads us to explore and analyse empirical phenomena that have not traditionally been part of the data-base considered for theorizing about the human language faculty. Conversely, by taking a generative perspective we are led to explore questions of universality and variation in the domain of interactional language, something that has not been systematically considered within other frameworks.