Key Concepts in TGG

1. Competence and Performance

Chomsky's objection to analyses of corpora is based on the distinction that he draws between two concepts: competence and performance.

1.1. Competence

Competence refers to a person's internalised grammar (knowledge) of his language. This means a native speaker's ability to produce and understand sentences, including sentences they have never heard before. It also includes a person's knowledge of what are and what are not sentences of a particular language. So, it is the code which underlies all utterances in a given language. A speaker's linguistic competence enables him to produce only grammatical and well-pronounced sentences, and to avoid the generation of ungrammatical and mispronounced sentences, and to recognise whether sentences are synonymous, ambiguous, simple, complex, etc. For Chomsky, linguistics should be concerned with competence. The latter is purely linguistic.

This is similar to Saussure's concept of langue, but Saussure stressed the social aspect of langue (the collective shared knowledge), whereas Chomsky stressed the individual nature of competence: He sees it as a set of processes possessed by the individual and developed in him as part of his maturation. “Langue” is extracted from utterances after they were produced, but “competence” is the system which creates sentences never heard before.

1.2. Performance

Performance, on the other hand, refers to the realisation of this code in actual situations. It is the person's concrete use of language in producing and understanding sentences. Performance represents only a small sample of the utterances of language and is influenced by external non-linguistic factors such as lapses of memory, lapses of attention, malfunctioning of the mechanisms related to speech, stress, fatigue, noisy surroundings and so on. As a result, a speaker may produce false starts, changes of plan in mid-course, restructuring of what the speaker wants to say, etc.

Performance is the use of the code in actual situations.  Competence is a linguistic code (set of rules)

For Chomsky, “performance” is not the object of study in linguistics (but psychology). For Saussure, however, “parole” does provide the data from which statements about “langue” can be made.

2. Deep Structure and Surface Structure

 
Chomsky, rejecting the formal analysis of sentences, distinguishes two levels of syntactic struucture in a sentence: the surface structure and the deep structure.

The surface structure (SS) is the syntactic structure of the sentence which a person speaks or hears: it is the observable form of the sentence. Chomsky argues that any analysis based on the surface structure encounters difficulties. Therefore, another level of sentence structure should be taken into account. The deep structure (DS) is much more abstract and is considered to be in the speaker's mind. It refers to certain important generalisations about the structure of the sentence which are different from its surface. The deep structure contains all the syntactic information needed for the understanding of a given sentence. The deep structure is converted into a surface structure after the application of a specific kind of rules called transformational rules (TRs). 

                                                      DS--------------- TRs----------------------- SS

Examples

• John is eager to please. (I)
•  John is easy to please. (II)

In the deep structures of these two sentences, it is clear that “John” is either the subject of pleasing or its object.
This distinction between surface and deep syntax became a major dichotomy in TGG, and, for many people, it is the main difference between the old and new approaches to syntax. For Chomsky, grammar is not confined to formal description but it should incorporate the internal processes that take place in the speaker's mind.

3. The Mentalist Attitude

 
According to Chomsky, language is creative and behaviourism is totally unable to explain creativity. He argues that the comparison of the sentences a speaker has heard (the input) with the sentences a speaker produces (the output) shows differences between them. That is to say, the output contains sentences the speaker has never heard before. On the basis of this evidence, one can deduce that there is “something” between the input and the output. Chomsky calls it the Language Acquisition Device (LAD)

Input ----------------- LAD -------------------- output

The LAD is an inborn capacity (a genetic mechanism or apparatus) which is present in the brain right from the beginning and which enables children (by the age of 3 to 4) to extract the rules of language from speech when they are exposed to it and to use them productively. Animals do not possess this capacity. For this reason, their learning of language-like behaviour stops at a definite stage even if they are exposed to it. 

Language acquisition takes place not as a result of imitation (stimulus + response) but as a result of the functioning of the LAD. In fact, what happens is that the child, when exposed to adult language, tries mentally to form hypotheses about its rules, then he tests the validity of these rules continuously and adapts them until he internally masters the abstract system of rules that adults have as part of their competence. So, language acquisition is part of the maturational process.

This view about language learning is called mentalism. It is based on the premise that human beings possess minds.

4. Language Universals

Chomsky sees that linguistic theory should be concerned with linguistic universals, i.e with the common characteristics between human languages. According to him, the deep structure is common, and languages differ only at the level of transformational rules which produce different surfaces.

5. Chomsky's Definitions of Language and Grammar

For Chomsky, "A language is a set (finite or infinite) of sentences, each finite in length and constructed out of a finite set of elements."(Syntactic Structures, p.13). This definition concerns all languages (natural and man-made). It implies the following points:

•  Language is a collection of the infinite number of possible sentences.
•  Every sentence is finite in length.
•  Every sentence is made up of elements that can be collected in a set, and that can be counted (sounds, morphemes and words)
• Language is defined in terms of “sentences”

Grammar is defined as "a device which generates all and only the grammatical sentences of a language." This definition implies the following points:

• The sentence is the basic unit to be described by grammar.
• A grammar generates sentences. That is to say, it produces an infinite number of sentences out of precisely specified rules. 
•  The rules of generative grammar represent knowledge.
• A grammar generates “all and only” the grammatical (intuitively accepted as well-formed) sentences of a language. That is to say, grammar should be able to generate all possible grammatical sentences of the language, and it excludes the ungrammatical (ill-formed) ones.

Grammaticality is the most important thing in the description of sentences.