The feature underspecification in relative clauses: A comparative study on mandarin-speaking children with...

This study examined how Mandarin-speaking children with Developmental Language Disorder (DLD) and Autism Plus Language Impairment (ALI) comprehend relative clauses (RCs), focusing on potential differences between subject and object RCs across these clinical populations. Both clinical groups demonstrated significant difficulties with RC comprehension, producing comparable error types: thematic role reversals, middle errors, and simple sentence errors. However, distinct performance patterns emerged: children with DLD showed better performance on subject RCs than object RCs, while children with ALI exhibited uniformly low performance across both RC types, suggesting potentially different underlying mechanisms. In line with the Edge Feature Underspecification Hypothesis, our findings suggest that the observed asymmetry in RC comprehension among children with DLD, as well as the error patterns across both clinical groups, may be explained by underspecified edge features.