Language learning - physiological and psychological aspects

There are several stages in the linguistic development of a child; he will not merely reproduce the sentences he hears, but a personal production is often noticed. Children do not acquire the grammar of their native language through theoretical teaching; exposure to the speaking community will lead to the acquisition of the grammatical structures of their language. Little is known about how little children acquire the rules of their native language; yet, we may distinguish between physiological and psychological aspects.