The document discusses speech act theory, which investigates how meaning can be derived from utterances beyond just their literal semantic meaning. It covers key aspects of speech act theory including locutionary acts (the literal meaning), illocutionary acts (the intended meaning or force), and perlocutionary acts (the effect on the listener). Examples are provided of direct speech acts where the structure matches the function (e.g. a question uses interrogative form) and indirect speech acts where the structure differs from the function (e.g. a statement used as a request). Major classifications of speech acts are presented, including representatives, directives, commissives, expressives, and declarations.