In the late 1960’s the concept of deep structure was reexamined owing to a growing need to relate syntactic description with meaning. Transformational-generative grammar divided into two schools.
The first school, headed by R. Jackendoff and R. Dougherty, was that of interpretive semantics. It retained the concept of deep structure but permitted rules of semantic interpretation that use information other than the information contained in the deep structure. The second school, that of generative semantics, rejected the concept of deep structure and developed rules for generating the sentences of a language directly from their semantic representations. The main representatives of this school are G. Lakoff, J. McCawley, J. Ross, and P. Postal.
TG is based on the concept of a universal grammar (UG) which is the set of rules for language that all humans possess thanks to the common genetic features which distinguish them from other organisms and make them ""human.""
When it comes to syntax, [Noam] Chomsky is famous for proposing that beneath every sentence in the mind of a speaker is an invisible, inaudible deep structure, the interface to the mental lexicon. The deep structure is converted by transformational rules into a surface structure that corresponds more closely to what is pronounced and heard. In transformational grammar, the term 'rule' is used not for a precept set down by an external authority but for a principle that is unconsciously yet regularly followed in the production and interpretation of sentences. A rule is a direction for