kernel sentence
in early versions of generative grammar, a base version of a sentence upon which such operations as negation and interrogation are performed to produce variations of that base. For example, the kernel sentence Jack kissed Jill can be transformed into the sentences Did Jack kiss Jill?, Jack did not kiss Jill, Jill was kissed by Jack, and so forth. Psychological interest in this idea stems from its implications for the cognitive processes by which we form and interpret sentences. In later models of transformational generative grammar, the transformational rules are seen as operating upon the deep structures underlying sentences, rather than on any actual sentence.