A study of specific language impairment (SLI) in the context of non-standard dialect

This study examines children's use of non-standard dialect and the effect of its use on standard measures of linguistic complexity and on the characterization of specific language impairment (SLI). Data involved spontaneous language samples from 31 children, aged 4-6 years, who lived in a rural area of southeastern Louisiana. A third of the children were diagnosed with SLI; the others were normally developing and matched to the children with SLI by either chronological age (CA) or mean length of utterance (MLU). Results indicated that the children produced 12 different dialectal structures, and for all but two children their use of non-standard forms occurred in less than 10% of their utterances. The presence of dialect did not significantly alter the children's scores for MLU, DSS, and IPSyn; however, for the age range studied here, IPSyn was found to be insensitive to childhood language impairment. Characterization of SLI as involving limitations of morphosyntax also was not significantly affected by the children's use of dialect. Whereas the normally developing children's use of morphology was either age-appropriate or attributable to a particular dialectal pattern, children with SLI demonstrated morphological limitations that were not expected for their age, MLU, or use of non-standard forms.