Types of speech acts :
Pretheoretically, we think of an act of communication, linguistic or otherwise, as an act of expressing oneself. This rather vague idea can be made more precise if we get more specific about what is being expressed. Take the case of an apology. If you utter, ‘[I'm] sorry I didn’t call back’ and intend this as an apology, you are expressing regret for something, in this case for not returning a phone call. An apology just is the act of (verbally) expressing regret for, and thereby acknowledging, something one did that might have harmed or at least bothered the hearer. An apology is communicative because it is intended to be taken as expressing a certain attitude, in this case regret. It succeeds as such if it is so taken. In general, an act of communication succeeds if it is taken as intended. That is, it must be understood or, in Austin’s words, ‘produce uptake’. With an apology, this a matter of the addressee recognizing the speaker’s intention to be expressing regret for some deed or omission. Using a special device such as the performative ‘I apologize’ may of course facilitate understanding (understanding is correlative with communicating), but in general this is unnecessary. Communicative success is achieved if the speaker chooses his words in such a way that the hearer will, under the circumstances of utterance, recognize his communicative intention. So, for example, if you spill some beer on someone and say ‘Oops’ in the right way, your utterance will be taken as an apology for what you did.
In saying something one generally intends more than just to communicate–getting oneself understood is intended to produce some effect on the listener. However, our speech act vocabulary can obscure this fact. When one apologizes, for example, one may intend not merely to express regret but also to seek forgiveness. Seeking forgiveness is, strictly speaking, distinct from apologizing, even though one utterance is the performance of an act of both types. As an apology, the utterance succeeds if it is taken as expressing regret for the deed in question; as an act of seeking forgiveness, it succeeds if forgiveness is thereby obtained. Speech acts, being perlocutionary as well as illocutionary, generally have some ulterior purpose, but they are distinguished primarily by their illocutionary type, such as asserting, requesting, promising and apologizing, which in turn are distinguished by the type of attitude expressed. The perlocutionary act is a matter of trying to get the hearer to form some correlative attitude and in some cases to act in a certain way. For example, a statement expresses a belief and normally has the further purpose of getting the addressee form the same belief. A request expresses a desire for the addressee to do a certain thing and normally aims for the addressee to intend to and, indeed, actually do that thing. A promise expresses the speaker’s firm intention to do something, together with the belief that by his utterance he is obligated to do it, and normally aims further for the addressee to expect, and to feel entitled to expect, the speaker to do it.
Statements, requests, promises and apologies are examples of the four major categories of communicative illocutionary acts: constatives, directives, commissives and acknowledgments. This is the nomenclature used by Kent Bach and Michael Harnish, who develop a detailed taxonomy in which each type of illocutionary act is individuated by the type of attitude expressed (in some cases there are constraints on the content as well). There is no generally accepted terminology here, and Bach and Harnish borrow the terms ‘constative’ and ‘commissive’ from Austin and ‘directive’ from Searle. They adopt the term ‘acknowledgment’, over Austin’s ‘behabitive’ and Searle’s ‘expressive’, for apologies, greetings, congratulations etc., which express an attitude regarding the hearer that is occasioned by some event that is thereby being acknowledged, often in satisfaction of a social expectation. Here are assorted examples of each type:
Constatives: affirming, alleging, announcing, answering, attributing, claiming, classifying, concurring, confirming, conjecturing, denying, disagreeing, disclosing, disputing, identifying, informing, insisting, predicting, ranking, reporting, stating, stipulating
Directives: advising, admonishing, asking, begging, dismissing, excusing, forbidding, instructing, ordering, permitting, requesting, requiring, suggesting, urging, warning
Commissives: agreeing, guaranteeing, inviting, offering, promising, swearing, volunteering
Acknowledgments: apologizing, condoling, congratulating, greeting, thanking, accepting (acknowledging an acknowledgment)
Bach and Harnish spell out the correlation between type of illocutionary act and type of expressed attitude. In many cases, such as answering, disputing, excusing and agreeing, as well as all types of acknowledgment, the act and the attitude it expresses presuppose a specific conversational or other social circumstance.
For types of acts that are distinguished by the type of attitude expressed, there is no need to invoke the notion of convention to explain how it can succeed. The act can succeed if the hearer recognizes the attitude being expressed, such as a belief in the case of a statement and a desire in the case of a request. Any further effect it has on the hearer, such as being believed or being complied with, or just being taken as sincere, is not essential to its being a statement or a request. Thus an utterance can succeed as an act of communication even if the speaker does not possess the attitude he is expressing: communication is one thing, sincerity another. Communicating is as it were just putting an attitude on the table; sincerity is actually possessing the attitude one is expressing. Correlatively, the hearer can understand the utterance without regarding it as sincere, e.g., take it as an apology, as expressing regret for something, without believing that the speaker regrets having done the deed in question. Getting one’s audience to believe that one actually possesses the attitude one is expressing is not an illocutionary but a perlocutionary act.
Kent Bach, Routledge Encyclopedia of Philosophy entry