Most accounts of child language acquisition use as analytic tools
adult-like syntactic categories and schemas (grammars) with little
concern for whether they are psychologically real for young children.
Recent research has demonstrated, however, that children do not operate
initially with such abstract linguistic entities, but instead operate on
the basis on concrete, item-based constructions. Children construct
more abstract linguistic constructions only gradually - on the basis of
linguistic experience in which frequency plays a key role - and they
constrain these constructions to their appropriate ranges of use only
gradually as well - again on the basis of linguistic experience in which
frequency plays a key role. The best account of first language
acquisition is provided by a usage-based model in which children process
the language they experience in discourse interactions with other
persons, relying explicitly and exclusively on social and cognitive
skills that children of this age are known to possess.