A grammar of a language purports to be a description of the ideal speaker-hearer's intrinsic competence. If the grammar is, furthermore, perfectly explicit - in other words, if it does not rely on the intelligence of the understanding reader but rather provides an explicit analysis of his contribution - we may (somewhat redundantly) call it a "generative grammar".
- Chomsky (1969), a pag.4

[...] by a generative grammar I mean simply a system of rules that in some explicit and welldefined way assigns structural descriptions to sentences. Obviously, every speaker of a language has mastered and internalized a generative grammar that expresses his knowledge of his language [...] a generative grammar attempts to specify what the speaker actually knows, not what he may report about his knowledge [...] To avoid what has been a continuing misunderstanding, it is perhaps worth while to reiterate that a generative grammar is not a model for a speaker or a hearer. It attemps to characterize in the most neutral possible terms the knowledge of the language that provides the basis for actual use of language by a speaker-hearer.
- Chomsky (1969), a pag.8-9