Nouns in early lexicons: evidence, explanations and implications

Many theories of grammatical and lexical acquisition assume that children learn predominantly nouns, and specifically names of objects, when they first begin to acquire words in the second year. We show that the noun bias in early vocabularies is far from universal, and that it rests only in part on the acquisition of object names. An analysis of vocabulary composition from 45 children at 1;8 indicates that more nouns are acquired than all other word classes, but that of the nouns acquired only about half are the names of basic level object classes (BLOCs). An examination of the use of nouns in mother-child discourse shows that non-object words referencing locations, actions and events, for example, are used in distinctive pragmatic and grammatical contexts which might enable a child to grasp the word's use and eventually its meaning. It is concluded that a theory of lexical acquisition in discourse context is required to explain word learning at all levels and for all word types. Implications for semantic bootstrapping theories are considered.