Request, affirm, alert, offer, promise, threaten, declare ... - these are just some of the actions we humans perform when we communicate. A key question in animal communication studies is which sorts of communicative actions non-human animals can perform. In this talk, I will attempt to sketch an answer to this question. To do so, I first give reasons that explain the apparent similarities between humans’ communicative acts, so called "speech acts", and those of nonhuman animals. Second, I explain the main problems with the two dominant approaches to illocutionary acts currently on offer, Gricean intentionalism and Austinian normative conventionalism. Thirdly, I sketch out a new theory of illocutionary acts that is capable of accommodating both human and animal’s communicative interactions. On this theory, each type of illocutionary act is characterised by the functions of the signal and those of the response which constitute a communicative interaction. The final section of the talk discusses some advantages and consequences of the theory.