A series of lectures developing a general pragmatic theory of human verbal communication. Lecture 1 poses the question how linguistic communication is possible, and criticizes theories of the 'message model'-type. Lecture 2 outlines an alternative theory, including a definition and taxonomy of illocutionary acts, systems of pragmatic strategies, of mutual contextual beliefs, of communicative and conversational presumptions, and an account of nonliteral, indirect, and standardized illocutionary acts. Lecture 3 gives some descriptive content (with respect to English) to this theory suggesting that the correlations of form, function, and fit are central to the account of understanding literal and direct communication. Lecture 4 surveys some of the psychological literature and adduces empirical evidence for this inferential approach to linguistic communication.