Transformational generative grammar - If we were to attempt to extend phrase structure grammar to cover the entire language directly, we would lose the simplicity of the limited phrase structure grammar and of the transformational development. This approach to syntactic analysis is not appreciable.
Chomsky in `Syntactic Structures' observes that "notions of phrase structure are quite adequate for a small part of the language and that the rest of the language can be derived by repeated application of a rather simple set of transformations to the strings given by the phrase structure grammar. Thus "Transformational Generative Grammar" was introduced. The name suggests that there are two aspects of this theory. The grammar that it provides is both `transformational' and `generative'. These two aspects are not logically dependent upon each other, though the theory gains plausibility from the interaction of the two.
TRANSFROMATIONAL: "Essentially", transformation is a method of stating how the structures of many sentences in languages can be generated or explained formally as the result of specific transformations applied to certain basic sentence structures.", as R. H. Robins observes in his book "General Linguistics". Further, he says, "These basic sentence types or structures are not necessarily basic or minimal from the point of view of Immediate Constituent Analysis, the transformational syntax presupposes a certain amount of phrase structure grammar of the immediate constituent type to provide the basis of the `kernel' from which transformations start." Thus active sentences are `kernel' sentences whereas passive sentences are the transforms. However, the notion of `kernel' has been abandoned by Chomsky since the publication of his "Aspects of the Theory of Syntax".
In TG sentence refers to the individual elements of which a language contains an infinite number. Grammar is the concept which refers to finite system which specify and generate these infinite number of sentences. TG has a comprehensive approach as it deals with the language on the syntactic, semantic, and phonological level which three put together represent language in both its structural and functional terms. No other grammar is complete in this sense.
(a) Harry loves Mary.
In this sentence three lexical items have been put together. This does not tell us anything
about meaning. The same words can be put into another order.
(a) and (b) have the same lexical items but different meaning. Similarly the phonological aspects pronunciation, intonation, stress can change the meaning of the structure. Thus syntax combines in semantics and phonological aspects which are integral to language as an integral whole.
[phonology]------[syntax]------[semantics]
The roles of the three components are not equal. The syntax has no input; it generated with rules and lexicon infinite number of sentences. The other two components operate on the structure specified by the syntax assigning further structure of them. Thus we have two aspects of syntactic structure.
Deep structure is the aspect of syntactic structure operated on by semantics for the purpose of semantic interpretation. Surface structure is the aspect of syntactic structure operated on by phonology for the purpose of phonetic interpretation. The surface structure is more immediately obvious and the deep structure takes into consideration the transformation. TG accentuates that the structures relevant for semantic interpretation turn out to be different from those which are relevant for phonological interpretation.
The following example is a simple model of how TG operates.
The boy killed the dog.(surface structure)The dog killed the boy. (deep structure)
