There is a language acquisition device called by Chomsky. He believes that language is somewhat innate, and that children are born with it. The theory reflects that children are born with the knowledge of the basic grammatical relations and categories, and this knowledge is universal. Besides, this knowledge throws some light on the nature of the human kind. Chomsky’s innateness hypothesis is based on his observations that some important facts can never be otherwise explained adequately. And his theory suggested that although babies are not born knowing a language, they are born with a predisposition to develop a language in much the same way as they are born with a predisposition to learn to walk.
The next stage is that the development of the Generative Grammar. For it, Chomsky simply means a system of rules that in some explicit and well-defined way assigns structural descriptions to sentences. He believes that every speaker of a language has mastered and internalized a generative grammar that expresses his knowledge of his language. A generative grammar is not limited to particular languages, but to reveal the unity of particular grammars and universal grammars. It does not describe one language as an end, but as a means to explore the universal rules in the hope of revealing human cognitive systems and the essential nature of human beings.
The third is the classical theory. In the classical theory, Chomsky’s aim is to make linguistics a science. This theory is characterized by three features: (1) emphasis on generative ability of language; (2) introduction of transformational rules; and (3) grammatical description regardless of meaning. The main idea can be found in Chomsky’s Syntactic Structures.
The fourth theory, the Standard Theory, is marked by Aspects of the Theory of Syntax. After the publication of his Syntactic Structures, Chomsky found serious problems that called for solution in order to reach his theoretical goals. The first problem is that the transformational rules are too powerful. An ordinary sentence can be transformed at will, negated, passivised, with certain elements added or deleted, without restrictions. The second problem is that his rules may generate ill-formed sentences as well as well-formed ones. In his Aspects of the Theory of Syntax, Chomsky made a remarkable change by including a semantic component in his grammatical model. He says that a generative grammar should consist of three components: syntactic, phonological and semantic.
The extended standard theory is the fifth theory. Chomsky revised his standard theory twice. In spite of the revisions of the classical theory made in the standard theory, there are still a lot of problems to be solved. Firstly, the transformational rules are still too powerful, tor they can move or delete linguistic segments, change the categories, keep the original meaning intact, and vary according to specific circumstances. Secondly, the standard theory holds that derived nouns such as criticism and explanation have the same semantic properties with their corresponding verbs.
In the 1980s, Chomsky’s TG Grammar entered the fourth period of development with the theory of government and binding. It consists of X-bar theory, Bounding theory, Government theory, Case theory, Control theory and Binding theory. Although all others had been mentioned in EST, the GB Theory further developed and complemented the discussions in EST.
Generally speaking, the development of TG grammar can be regarded as a process of constantly mineralizing theories and controlling the generative powers, and the Minimalist Program and the Minimalist Inquiries are just some logical steps in this process. Although TG Grammar has involved putting forward, revising, and cancelling of many specific rules, hypotheses, mechanisms, and theoretical models, its aims and purposes have been consistent.
Chomsky’s TG Grammar differs from the structural grammar in a number of ways: (1) rationalism; (2) innateness;(3) deductive methodology;(4) emphasis on interpretation;(5) formalization;(6) emphasis on linguistic competence;(7) strong generative powers;(8) emphasis on linguistic universals.
First, Chomsky defines language as a set of rules or principles. Second, Chomsky believes that the aim of linguistics is to produce a generative grammar which captures the tacit knowledge of the native speaker of his language. This concerns the question of learning theory and the question of linguistic universals. Third, Chomsky and his followers are interested in any data that can reveal the native speaker’s tacit knowledge. They seldom use what native speakers actually say; they rely on their own intuition. Fourth, Chomsky’s methodology is hypothesis-deductive, which operates at two levels: (a) the linguist formulates a hypothesis about language structure----a general linguistic theory; this is tested by grammars for particular languages, and (b) each such grammar is a hypothesis on the general linguistic theory. Finally, Chomsky follows rationalism in philosophy and mentalism in psychology.