Grammar is traditionally subdivided into two areas of study – morphology and syntax. Morphology is the study of how words are formed out of smaller units, syntax studies the way in which phrases and sentences are structured out of words.
Traditional grammar describes the syntax of a language in terms of a taxonomy (classification). This approach is based on the assumption that phrases and sentences are built up of a series of constituents, each of which belongs to a specific grammatical category and serves a specific grammatical function. In contrast to the taxonomic approach, linguist Noam Chomsky developed a cognitive approach to the study of grammar in which the study of language is part of the wider study of cognition. The goal of the linguist in the cognitive approach is to determine what is it that enables native speakers to speak and understand the language fluently. Any native speaker of a language can be said to know the grammar of his/her language. Native speakers have grammatical competence in their native language – they have tacit (subconscious) knowledge of the grammar of their language, they know how to form and interpret words, phrases and sentences.
Chomsky has drawn a distinction between competence -- the speaker-hearer’s knowledge of his language, and performance – the actual use of language in concrete situations. Every native speaker of a language makes occasional slips of the tongue or misinterprets something but this does not mean they do not know their native language, these are just performance errors attributable to various factors such as tiredness, drugs, external distractions and so on. The ultimate goal in studying competence is to characterise a mental state, the internalised linguistic system (I-language), which makes native speakers proficient in their language.
Chomsky’s ultimate goal is to devise a theory of Universal Grammar/UG – a theory about the nature of all possible grammars of human languages. This theory must satisfy a number of criteria of adequacy. It must be universal – provide a descriptively adequate grammar for any and every human I-language, it must satisfy the criterion of explanatory adequacy – explain why grammars have the properties they do, it has to be maximally constrained – limited in such a way that it can only be used to describe natural languages. The final important criterion is that grammars should be as simple as possible in the sense that they need to be learnable by young children in a short period of time.
Theory of language acquisition is focused on the question of how children acquire grammars of their native languages. The innateness hypothesis introduced by Chomsky, suggests that the course of language acquisition is determined by a biologically endowed innate Language Faculty within the brain, which provides children with a set of procedures for developing a grammar, on the basis of their linguistic experience. Research has suggested that there is a critical period for the...