Transformational-generative grammar is a theoretical grammar designed to explain the process and the rules that enable us to “know” how to generate an infinite number of grammatical sentences
and how to avoid truly ungrammatical ones), even though we cannot consciously describe what scheme it is we’re following
Generative grammar had its beginning particularly in the work of Zellig Harris and his student Noam Chomsky
. In 1957, Noam Chomsky published Syntactic Structures, in which he developed the idea that each sentence in a language has two levels of representation: a deep structure and a surface structure
The deep structure represented the core semantic relations of a sentence, and was mapped on to the surface structure (which followed the phonological form of the sentence very closely) via transformations.