Nominal versus verbal morpheme use in late talkers at ages 3 and 4.

Late talkers with normal receptive language and typically developing peers matched at 24- to 31-month intake on socieoeconomic status and nonverbal cognitive skills were compared at age 3 (N = 29, 20) and age 4 (N = 37, 16) on grammatical morpheme suppliance during speech samples. Age 4 late talkers differed from age 3 MLU-matched typically developing children on only the contractible copula. At age 4, "late bloomers" did not differ from typically developing children on any morpheme, but late talkers with "continuing delay" differed from comparison children on articles, nominative case pronouns, auxiliary be, and the contractible copula. Noun phrase morphemes were acquired earlier than verb phrase morphemes by both late talkers and comparison children, a nominal-verbal morpheme "decalage" that was first reported by R. Brown (1973). Results suggested that our late talkers did not have a selective deficit in verb morphology relative to their MLU. Findings are discussed in terms of a spectrum of SLI, with both late talkers and preschoolers with SLI hypothesized to have weaker endowments for language learning than typically developing children, but with late talkers being less impaired and thus closer to normal on this spectrum.