Is it possible to develop a comprehensive grammar of talk-in-interaction for a specific language based on descriptions of social actions? This is the question we will try to answer in this article. The article is based on the work of the project The Grammar in Everyday Life, which aims to build a systematic grammatical description of Danish talk-in-interaction based on descriptions of social action formats within three domains: question-answer sequences, commissive-directive sequences, and the negotiation of participation during longer spates of talk. Our ambition is to build a grammar that takes into consideration how talk is used in the real-time unfolding of interaction to do actions and to negotiate relationships. Through a presentation of three formats, we discuss how a grammatical description can be organized, how granular it should be, if and how traditional grammatical categories can be used, and how prosodic and embodied features could be included. Data are in Danish.