Use of noun morphology by children with language impairment: the case of Hungarian.

BACKGROUND Children with language impairment often exhibit significant difficulty in the use of grammatical morphology. Although English-speaking children with language impairment have special difficulties with verb morphology, noun morphology can also be problematic in languages of a different typology. AIMS Hungarian is an agglutinating language with multiple suffixation, in which both regular-class and irregular-class nouns contain the same recognizable grammatical markers, but the two classes differ in their morphophonology and productivity. Such typological characteristics provide a good basis for evaluating processing accounts of language impairment such as the morphological richness account. METHODS & PROCEDURES We examined the production of Hungarian irregular and regular noun morphology through elicited production of nouns with plural, accusative case and plural plus accusative case suffixes in an older (8-10 years) and a younger (4-7 years) group of children with language impairment and two verbal control groups matched on vocabulary size. The children's accuracy was scored both in terms of grammatical function (whether plural and/or accusative case was appropriately marked) and morphophonology (whether the production reflected the phonotactic form required for the stem plus suffix). OUTCOMES & RESULTS The younger children with language impairment were less accurate than the younger verbal control children when two suffixes (marking plural and accusative case) were required, at least when noun stem classes were regular. All groups showed significant overgeneralization of stem forms with correct selection of suffixes. However, there were strong word frequency effects in the language impairment, but not in the verbal control groups. CONCLUSIONS & IMPLICATIONS Much of the data were consistent with predictions of the morphological richness account. However, there was also evidence suggestive of differences between the language impairment and verbal control groups in their representations. In particular, the children with language impairment seemed to rely more (though not exclusively) on memorized items in the lexicon.