Subject-verb agreement in Down Syndrome

While studies on English individuals with Down syndrome (DS) report impaired performance with the production of subject-verb (S/V) agreement, Schaner-Wolles (2004) shows close to ceiling performance with the production of S/V agreement for German indi­viduals with DS. This study reports on findings from the production of S/V agreement of Cypriot Greek adults diagnosed with DS and offers preliminary predictions with the purpose of disambiguating whether individuals with DS present a cross-linguistic impairment. The production of inflectional person and number marking was examined with sixteen Cypriot Greek individuals with DS and seventeen typically developing children, through nine sponta­neous and controlled elicitation tasks. The morphosyntactic analysis reveals close to ceiling performance with 98.5% accuracy for person and 99% accuracy for number. Results revealed a clear systematicity in selecting the default value for each inflectional feature: the 3rd value for person and the singular value for number. Considering results from seven languages, it is predicted that the underlying coping strategy, whether it surfaces as an optional infinitive or a default feature value, is the same; namely, the use of a default form

Agreement · Default · German · Infinitive · Down syndrome and intellectual disability research · Language Development and Disorders · Williams Syndrome Research