This document discusses speech act theory, which proposes that language is used not just to inform or describe, but also to perform actions or "do things". It provides examples of speech acts like firing someone or making a promise. The document outlines three types of speech acts: locutionary acts (the literal meaning), illocutionary acts (the implied meaning or force), and perlocutionary acts (the effect on the listener). It discusses how context can change the implied meaning or force of an utterance. The document also covers indirect speech acts, ironic speech acts, silence as a speech act, and different functions of speech acts like exchanging information, persuading, or socializing.