Specific Language Impairment and Grammatical Morphology: a Discriminant Function Analysis

Discriminant function analysis was employed to determine if grammatical morpheme production could be used to classify preschool-age children with specific language impairment (SLI) and children with typically developing language skills. Three variables were included in the discriminant analysis: a finite verb morpheme composite, a noun morpheme composite, and mean length of utterance in morphemes. The children with SLI and age-matched controls were discriminated with high levels of accuracy, though the three variables did not yield identical classifications. Across two samples of typically developing children and children with SLI, the verb morpheme composite showed sensitivity exceeding 85% and specificity of 100%. In light of these results and growing evidence that problems with finite verb morphology continue into the school years in children with SLI, the verb morpheme composite was considered to hold promise as a clinical marker for SLI.