Acquisition of German Noun Plurals in Typically Developing Children and Children with Specific Language Impairment

The present study investigates the acquisition of plural markers in German children with and without language impairments using an elicitation task. In the first cross-sectional study, 60monolingual children between three and six years of age were tested. The results showsignificant improvements starting at the age of five. Plural forms which require a vowelchange (umlaut) but no overt suffix were most challenging for all children. With regard totheir error patterns, the typically developing children preferably overapplied the suffix -e tomonosyllabic stems and added -s to stems ending in a trochee. Though the children madeerrors in plural markings, the prosodic structures of pluralized nouns were kept legitimate. In the second study, the production of plural markers in eight children with SLI was comparedto age-matched and MLU-matched controls. Children with SLI performed at the level of theMLU-matched controls, showing subtle differences with regard to their error patterns, andtheir preferences in addition and substitution errors: In contrast to their typically developingpeers, children with SLI preferred the frequent suffix -n in their overapplications, suggestingthat they strongly rely on frequency-based cues. The findings are discussed from amorphophonological perspective