The perfective past tense in Greek children with specific language impairment

This study presents experimental results examining the production of perfective past tense forms of Greek in eighteen individuals with Specific Language Impairment (SLI) in comparison to typically developing children. We found that both individuals with SLI and typically developing children were more accurate in producing sigmatic than non-sigmatic verb forms. On the other hand, children with SLI were found to be impaired in their use of sigmatic forms and to over-rely on non-sigmatic forms, relative to typically developing children. We discuss linguistic and neuro-psychological accounts of these findings. In addition, we compare the SLI data with data from individuals with a different genetic disorder (Williams Syndrome), and show that individuals with Williams Syndrome exhibit different performance patterns.