Our aim in this paper is to explore the variety of ways in which grammar can be used as a resource for interaction. We propose that a grammatical analysis of social interaction needs to take two perspectives into account. The first involves showing how the meaning of a grammatical unit depends on its context of use (Schegloff 1996). The second involves identifying speakers’ specific choices of grammatical categories (e.g., verbs, nouns, etc.) and showing how these categories combine to create specific inference-rich meanings (Halliday 1978, 1994). Drawing from couples therapy data, we show that by adopting grammatical categories into our analysis, a unique perspective on the moment-to-moment unfolding of therapy can be provided.