Studied the linguistic competence in the written language of deaf children and adults and the linguistic development in children and adolescents with Williams Syndrome. Presents qualitative data on spoken and written Italian from cross-sectional and longitudinal studies conducted over the last 10 years. Studying these two different populations can…

Data from 34 children suggest that a range of Italian grammatical morphemes reach the level of mastery by age 3;6-4;0. In the period between 2;6 and 3;0, as use and comprehension of morphemes are being consolidated, homonymy and informativeness seem not to play a role, though number continues to exert an influence. Some form classes of Italian are…