The Emergence of Verb Patterns in Arabic in Children With Developmental Language Disorder Compared to Children With Typical Development.

Purpose: The Arabic verb system features a nonlinear root and pattern derivational morphology. Previous studies suggest that young Arabic and Hebrew speakers' early verb use is based on semantic complexity rather than derivational morphological structure. The present study examines the role of morphological and semantic complexity in the emergence of the verb morphology in Arabic speaking children with developmental language disorder (DLD) compared to children with typical language development (TLD).

Method: Natural language data were collected from native Arabic-speaking children (40 with DLD; aged 4-6 years and 133 with TLD aged 2;6-6;0 [years;months]) using picture-based elicitation tasks, and verbs were coded morphologically for derivational features and for features of semantic complexity.

Results: The results showed that children with DLD demonstrated a more limited production of verb patterns, both in types and in tokens, than age-matched children with TLD. Also, children with DLD age 5;0-6;0 were similar in types and tokens of verb patterns to younger children with TLD at the age of 3;6-4 years. Moreover, while children with TLD at the age of 2;6-3 years used a smaller number of verb patterns than older 4;0-5;0 aged children with DLD, the two groups were not different in verb semantics. Finally, the morphological and semantic diversity demonstrated by the children with DLD was similar to the morphological and semantic diversity shown by children with TLD.

Conclusion: Our findings support the conclusion that children with DLD and with TLD acquire the derivational verb system in the same pathway and the quantitative lexical differences between the two groups support a delay rather than a deviation from the typical developmental trajectory.