Syntax in Spanish-speaking children with Williams syndrome

• Children with Williams syndrome perform worse than their peers matched in chronological age in all tasks.
• Compared to their peers matched in verbal age they perform worse only in sentences containing cross-serial dependencies.
• They are more sensitive to semantic cues than to syntactic constraints.
• The exhibit a poorer lexical knowledge of some functional words (specifically, of non-reflexive pronouns).
• A processing bottleneck or a computational constraint may account for this outcome.

The syntactic skills of Spanish-speaking children with Williams syndrome (WS) were assessed in different areas (phrase structure, recursion, and bound anaphora). Children were compared to typically-developing peers matched either in chronological age (CA-TD) or in verbal age (VA-TD). In all tasks children with WS performed significantly worse than CA-TD children, but similarly to VA-TD children. However, significant differences were observed in specific domains, particularly regarding sentences with cross-serial dependencies. At the same time, children with WS were less sensitive to syntactic constraints and exhibited a poorer knowledge of some functional words (specifically, of nonreflexive pronouns). A processing bottleneck or a computational constraint may account for this outcome.