Several hypotheses have been offered to explain the grammatical morpheme difficulties observed in the speech of children with specific language impairment. Three of the accounts that could be evaluated in English were the focus of this study: the extended optional infinitive account, the implicit rule deficit account, and the surface account. Preschoolers with specific language impairment, a group of age controls, and a group of younger children matched for mean length of utterance were evaluated in their use of several theory-relevant grammatical morphemes. The findings revealed advantages for both the surface and extended optional infinitive hypotheses. In contrast, a test of the predictions based on the implicit rule deficit account suggested that the children studied here were not experiencing a deficit of this type.

No abstract

We investigated whether preschool children with specific language impairment (SLI) exhibit the shape bias in word learning: the bias to generalize based on shape rather than size, color, or texture in an object naming context ('This is a wek; find another wek') but not in a non-naming similarity classification context ('See this? Which one goes with this one?'). Fifty-four preschool children (16 with SLI, 16 children with typical language [TL] in an equated control group, and 22 additional children with TL included in individual differences analyses but not group comparisons) completed a battery of linguistic and cognitive assessments and two experiments. In Experiment 1, children made generalization choices in object naming and similarity classification contexts on separate days, from options similar to a target object in shape, color, or texture. On average, TL children exhibited the shape bias in an object naming context, but children with SLI did not. In Experiment 2, we tested whether the failure to exhibit the shape bias might be linked to ability to detect systematicities in the visual domain. Experiment 2 supported this hypothesis, in that children with SLI failed to learn simple paired visual associations that were readily learned by children with TL. Analyses of individual differences in the two studies revealed that visual paired-associate learning predicted degree of shape bias in children with SLI and TL better than any other measure of nonverbal intelligence or standard assessments of language ability. We discuss theoretical and clinical implications.

The present findings are in harmony with the notion that the participants with TBI studied presented with impairments of both micro- and macrolinguistic processes involved with the organization of semantic information in discourse. Clinical implications are discussed.

The purpose of the present study was to investigate the influence of argument-structure complexity on the omission of auxiliary be verbs in a group of children with specific language impairment (SLI). These children were compared to a group of younger, normally developing children matched for mean length of utterance (MLU) and a group of children matched for chronological age (CA). Using a story-completion task, the children (N = 30) were required to produce sentences of varying length and argument-structure complexity. The results of the study indicated that the children with SLI omitted more auxiliary forms than either the MLU or CA controls. In addition, both the children with SLI and the MLU controls were more likely to omit the auxiliary forms when attempting sentences with greater argument-structure complexity. These results suggest that argument-structure complexity may be a contributing factor to children's omissions of grammatical morphemes.

The purpose of this study was to evaluate children with specific language impairment (SLI) and their proficiency with the use of prepositions. Ten children with SLI were compared to 10 younger, normally developing children matched for mean length of utterance and 10 children matched for age. Each child was asked to produce 24 sentences containing locative (in, on) and dative (to) prepositions. Responses were coded for omission or word selection errors for the target prepositions. It was hypothesized that children with SLI would make more errors than the typically developing children. Omission errors would support a difficulty with syntax because of the role prepositions play in case marking. Word selection errors would support a deficit in the area of semantics. The results confirmed that children with SLI made more errors than the control group. The children with SLI made more errors in the selection of dative prepositions, indicating a difficulty linking the semantics of prepositions and verbs.

The language transcripts of seven children with Down syndrome and seven typically developing children matched for comparable MLU levels were compared for several measures of lexical diversity. These measures were percentage of utterances containing lexical verbs, number of verb tokens produced, a mean number of verbs per utterance (MVU), number of verb types used, and number of mental state verbs used. The results of this study indicated that the children with Down syndrome produced lexical verbs as frequently as their normally developing counterparts. In contrast, the children with Down syndrome were found to produce a larger variety of lexical verbs. An examination of a subset of verbs indicated that both groups of children produced an equal number of mental state verbs. These results support previous findings that when compared to syntactic development, children with Down syndrome show a relative area of strength in expressive vocabulary.

The spontaneous utterances of children with specific language impairment (SLI ) were examined for their argument structure. The verbs used by the children were categorized into four types based upon the number and placement of their obligatory arguments. The categories consisted of unergative intransitives, unaccusative intransitives, transitives, and ditransitives. The results of the study revealed that children with SLI omitted subject arguments more frequently than their younger MLU-matched peers. Such omissions were most likely in sentences with unaccusative intransitives. These findings raise the possibility that children with SLI have difficulty with the movement required to achieve the surface representation of unaccusative verb constructions.