A speech act in linguistics and the philosophy of language is an utterance that has performative function in language and communication. According to Kent Bach, "almost any speech act is really the performance of several acts at once, distinguished by different aspects of the speaker's intention: there is the act of saying something, what one does in saying it, such as requesting or promising, and how one is trying to affect one's audience." The contemporary use of the term goes back to J. L. Austin's development of performative utterances and his theory of locutionary, illocutionary, and perlocutionary acts. Speech acts are commonly taken to include such acts as promising, ordering, greeting, warning, inviting and congratulating.