Comprehension of relative clauses was assessed in 10 Hebrew-speaking school-age children with syntactic SLI and in two groups of younger children with normal language development. Comprehension of subject- and object-relatives was assessed using a binary sentence-picture matching task. The findings were that while Hebrew-speaking children with normal development comprehend right-branching object relatives around the age of 6;0, children with syntactic SLI are still at chance level in object relatives by age 11;0. The four-year-olds were also at chance on object relatives. Comprehension of subject relatives was good in the SLI group, similar to the six-year-olds, and significantly better than the four-year-olds. The syntactic impairment is interpreted as a selective deficit to non-canonical sentences that are derived by movement.

The study explored the ability of children with syntactic SLI (S-SLI) to produce relative clauses, using two structured elicitation tasks. A preference task and a picture description task were used to elicit subject and object relative clauses. The participants were 18 Hebrew-speaking children with S-SLI aged 9;3 – 14;6, and the control group included 28 typically developing children aged 7;6 – 11;0. The rate of target responses as well as the types of other responses the S-SLI group produced were analysed and compared to the control group. The results of both tasks indicated that the children with S-SLI had a deficit in the production of object relatives. Their production of subject relatives was better, though below the performance of the control group. Several response types were used exclusively by the S-SLI group: avoidance of object relatives and production of subject relatives and simple sentences instead, thematic role errors and thematic role reduction. Importantly, the S-SLI children did not omit complementizers, nor did they make other structural errors. These results suggest that the deficit is related to thematic role assignment to moved constituents, and not to a structural deficit in embedding.