Notice, incidentally, that a descriptively adequate grammar is rather different from a general convention regarding the forms of the grammar. Summarizing, then, we assume that the speaker-hearer's linguistic intuition does not affect the structure of nondistinctness in the sense of distinctive feature theory. We will bring evidence in favor of the following thesis: the descriptive power of the base component can be defined in such a way as to impose the extended c-command discussed in connection with (34). To provide a constituent structure for T(Z,K), the fundamental error of regarding functional notions as categorial is not to be considered in determining the traditional practice of grammarians. A consequence of the approach just outlined is that a case of semigrammaticalness of a different sort is to be regarded as an important distinction in language use.
see also: WikiPedia -- Chomskybot