Speech acts are utterances that speakers use to achieve intended effects such as apologies, greetings, requests, complaints, invitations, compliments, or refusals. There are three types of speech acts: locutionary acts are the actual utterance, illocutionary acts are the social function or purpose of the utterance, and perlocutionary acts are the resulting effects of the utterance based on context. Additionally, Searle classified illocutionary acts into five categories: assertives express beliefs, directives try to make the listener perform an action, commissives commit the speaker to future actions, expressives convey feelings or reactions, and declarations bring about external changes through language alone.