When we speak, we mean more than we say. In this book Stephen C. Levinson explains some general processes that underlie presumptions in communication. This is the first extended discussion of preferred interpretation in language understanding, integrating much of the best research in linguistic pragmatics from the last two decades. Levinson outlines a theory of presumptive meanings, or preferred interpretations, governing the use of language, building on the idea of implicature developed by the philosopher H.P. Grice. Some of the indirect information carried by speech is presumed by default because it is carried by general principles, rather than inferred from specific assumptions about intention and context. Levinson examines this class of general pragmatic inferences in detail, showing how they apply to a wide range of linguistic constructions. This approach has radical consequences for how we think about language and communication.