In psychology, nativism is the idea that certain abilities are innate - ie they are "hard-wired" into the brain at birth. From the late 1950s, Chomsky argued that this was the case with language - that the human brain contains a neurological mechanism - which he called the Language Acquisition Device - that allows humans to "acquire" language (ie to become competent in a language from exposure and attempted use alone) while animals, though they may be exposed to identical input, never will.
In order for this to happen, Chomsky argued that all languages must, despite superficial differences, be based on a set of principles which can be recognised by the brain. This he called Universal Grammar. A simple example would be that certain grammatical categories - eg noun and verb - seem to be common to all languages. Obviously, this does not mean that the grammar of all languages will be identical - there will also be parameters which allow certain variations - but only within set limits. Cook (2008) gives the following example :
“To take an English example sentence “Max played the drums with Charlie Parker”, principles of phrase structure require every phrase in it to have a head of a syntactic category and permit it to have complements of various types; A Verb Phrase such as “played the drums” must have a head that is a verb, “play”, and may have a complement “the drums”, a Prepositional Phrase such as “with Charlie Parker” must have a head that is a preposition, “with”, and a complement “Charlie Parker”; Noun Phrases such as “Max”, “the drums”, and “Charlie Parker” must have noun heads and may, but in this case do not, have complements. This is not true only of English; the phrases of all languages consist of heads and possible complements – Japanese, Catalan, Gboudi and so on. The difference between the phrase structures of different languages lies in the order in which head and complement occur within the phrase; in English the head verb comes before the complement, the head preposition comes before its complement, while Japanese is the opposite. This variation in languages is captured by the head parameter, which has two settings “head first” and “head last” according to whether the head comes before or after the complement in the phrases of the language.”
Second Language Learning and Language Teaching