Verb morphology as clinical marker of specific language impairment: evidence from first and second language learners

The goal of this study was to search for verb morphology characteristics as possible clinical markers of SLI in Dutch as a first and second language. We also wanted to find out to what extent bilingual children with SLI are additionally disadvantaged in comparison to monolingual children with SLI, on the one hand, and to typically developing bilingual children, on the other hand. Therefore, we examined the use of verb morphology in the narratives of four groups of 7- and 9-year-old children: native Dutch (monolingual) children without SLI, bilingual children without SLI, native Dutch (monolingual) children with SLI, and bilingual children with SLI. The narrative performance in Dutch as measured by mean length of utterance and number of ungrammatical sentences was found to be generally worse for children learning Dutch as a second language, for children suffering from SLI, and for younger children. Furthermore, omission of an agreement marker in the third person singular verb form can be seen as a clinical marker of SLI in both first and second language learners. Bilingual children with SLI were found to be in an additionally disadvantaged position as far as their use of L2 verb morphology.