A language can be defined as an infinite set of well-formed sentences.As we have seen，there is no limit to the number of sentences in a language.A grammar is a formal device with a finite set of rules that generates the sentences in the language.This notion of generation is similar to the notion of deduction in mathematics or logic：we can deduce the sentences in a language by using the rules of the grammar.Grammars thus are theories of language，composed of more specific hypotheses about the structure or organization of some part of the language.Since the study of T-G Grammar representing generativism and Structuralist Grammar representing structuralism are closely related to the study of the G-T Method，and both of which dominate general linguistics and the application of linguistics to language teaching，the author of the present study will intend to discuss them in the following.

T-G Grammar recognizes language as a‘rule-governed’system.These rules which are‘not only intricate but also quite abstract’.（Chomsky，1966：47）are made explicit by a transformational generative grammar.‘Learning a language involves internalizing the rules.’（Saporta，1966：86）Structural linguistics，it was argued，is an understanding of a language as a system of rule-governed relationships.It treats a language merely as a collection of habits in language teaching，therefore，it sanctions imitation，memorization，mechanical drill，and practice of sentence patterns as separate and unrelated items.‘Having somehow stored a very large number of sentences cannot be equated with having learnt a language.’（loc.cit.）Chomsky accused linguists of having had their share in perpetuating the myth that linguistic behavior is“habitual”and that a fixed stock of“patterns”is acquired through practice and used as the basis for“analogy”（Chomsky，1966：44）.Structural linguistics by basing itself inductively on the utterances（the‘performance’or parole）of informants（‘want its native speakers say’）was accused of lacking criteria by which to distinguish the regular from the accidental，the grammatical from the ungrammatical.T-G Grammar，instead concerns itself with the native speaker's norm，i.e.，what he considers as ungrammatical or rejects as ungrammatical（the native speaker's‘competence’）rather than with the extent to which he obeys the norm，his performance（Anisfeld，1966：110）.

Structural linguistics was found wanting for another reason.It was only concerned with surface structure and important distinctions that deep-structure analysis revealed remained unrecognized.Consequently pattern practice in language teaching was often criticized for being misleading.Examples were cited which revealed the insensitivity of structuralism to deep structure.Because T-G Grammar emphasizes the difference between deep and surface structure，it was believed that it can deal more effectively than structuralism with structural similarities，differences，and ambiguities and can provide better insight into language.“The learning of fundamental syntactic relations and processes will not be accomplished by drill based on analysis of surface structure alone.”（Spolsky，1970：151）

Because of its emphasis on formal aspects，structural linguistics was accused of neglecting meaning.This criticism could equally well have been made of the 1957 version of T-G Grammar，but by the mid-sixties，when these criticisms were expressed，T-G Grammar had incorporated a semantic element，and it was therefore able to meet the charge against structuralism of an excessive concern with the purely formal characteristics of a language.‘When you learn a language，you have to learn its semantic system too’（loc.cit.）.

Because T-G Grammar was more interested in the native speaker's competence than his performance，the question of the phonetic manifestations of language was no longer so central.The primacy of speech，a cardinal tenet of structuralism，was called into question.The spoken language and the writing system do not correspond directly，and their complex relationships will receive the useful scrutiny they deserve only after linguists and language teachers abandon the notion that one is a direct representation of the other（Valdman，1966a：ⅩⅦ）.

An important feature of T-G Grammar was emphasis on the productive or creative character of language，which had no place in structuralism and other contemporary linguistic theory.The most obvious and characteristic property of normal linguistic behavior is that‘it is stimulus-free and innovative.’（Chomsky，1966：46）‘An infinite number of sentence can be produced by what seems to be a rather small finite number of grammatical rules.A speaker does not have to store a large number of readymade sentences in his head；he just needs the rules for creating and understanding these sentences.’（Diller，1978）

Lastly，structural linguistics was accused of over-emphasizing the differences between languages and the unique characteristics of each languag e.T-G Grammar，on the other hand concerned itself with the common elements the universals，underlying all natural languages.