Expository Discourse in Adolescents With Language Impairments: Examining Syntactic Development

PURPOSE: This study examined syntactic development in a large cohort of adolescents. At kindergarten, each participant had been identified as having specific language impairment (SLI), nonspecific language impairment (NLI), or typical language development (TLD). METHOD: The participants (n = 444) had a mean age of 13;11 (years;months; range = 12;10-15;5). Language samples were elicited in 2 genres, conversational and expository, and analyzed for mean length of T-unit and subordinate clause production. RESULTS: Mean length of T-unit and the use of nominal, relative, and adverbial clauses were greater during the expository task than the conversational task for all groups. Thus, even the SLI and NLI groups produced longer sentences containing greater amounts of subordination when speaking in the expository genre than in the conversational genre. No group differences were revealed by the conversational task. However, on the expository task, the TLD group outperformed both the SLI and NLI groups on mean length of T-unit, and the TLD group outperformed the NLI group on relative clause use. CONCLUSIONS: Speech-language pathologists may wish to employ expository discourse tasks rather than conversational tasks to examine syntactic development in adolescents.