Pragmatics is a systematic way of explaining language use in context. It seeks to explain aspects of meaning which cannot be found in the plain sense of words or structures, as explained by semantics.
Paul Grice proposes that in ordinary conversation, speakers and hearers share a cooperative principle. Speakers shape their utterances to be understood by hearers. The principle can be explained by four underlying rules or maxims. They are the maxims of quality, quantity, relevance and manner.
Leech's maxims: Tact maxim (in directives [impositives] and commissives): minimise cost to other; [maximise benefit to other]
Generosity maxim (in directives and commissives): minimise benefit to self; [maximise cost to self]
Approbation maxim (in expressives and representatives [assertives]): minimise dispraise of other; [maximise praise of other]
Modesty maxim (in expressives and representatives): minimise praise of self; [maximise dispraise of self]
Agreement maxim (in representatives): minimise disagreement between self and other; [maximise agreement between self and other]
Sympathy maxim (in representatives): minimise antipathy between self and other; [maximise sympathy between self and other]