Key Concepts in TGG

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.