Children's productions of the affix -ed in past tense and past participle contexts.

Children's productions of the affix -ed in past tense and past participle contexts (e.g., the boy kicked the ball vs. the ball was kicked) were examined in spontaneous conversations and elicited productions. The performances of 7 children with specific language impairment (SLI) were compared with those of 2 control groups of typically developing children (age matches, MLU matches). Children with SLI produced fewer obligatory contexts for both past tense and past participle forms than did the control children, and were more likely to omit past tense affixes. In contrast, few omissions of the past participle were observed across all 3 groups. Implications for theories regarding the morphological deficits associated with SLI are discussed.