Noun Case Suffix Use by Children with Specific Language Impairment: An Examination of Finnish.

Finnish-speaking children with specific language impairment (SLI, N = 15, M age = 5;2), a group of same-age typically developing peers (TD-A, N = 15, M age = 5;2) and a group of younger typically developing children (TD-Y, N = 15, M age = 3;8) were compared in their use of accusative, partitive, and genitive case noun suffixes. The children with SLI were less accurate than both groups of TD children in case marking, suggesting that their difficulties with agreement extend to grammatical case. However, these children were also less accurate in making the phonological changes in the stem needed for suffixation. This second type of error suggests that problems in morphophonology may constitute a separate problem in Finnish SLI.