Impairments of tense in a familial language disorder

Abstract

This paper reports an in-depth analysis of one particular aspect of familial language impairment: tense. The subjects in this study are all adults from a family in which half of the members exhibit severe difficulties in acquiring language while the other members of the family are not language impaired. Though these language impaired adult native speakers of English routinely produce sentences such as “The people in the house called the ambulance and the boy went to hospital,” which appear to be correctly marked for tense, they also produce sentences like, “She remembered when she hurts herself the other day,” in which the tense marking on the second verb does not agree with either the tense marking on the first verb or the semantic idea of “pastness” established by the temporal phrase. Data from tests of tense production, grammaticality ratings and spontaneous speech converge to suggest that the language impaired subjects do not have an intact underlying obligatory syntactic rule for tense, though they appear to have the semantic notion of “pastness.” The patterns of impairment include a willingness to produce and accept unmarked forms in obligatory contexts, an advantage in producing irregular verbs compared to regular ones, errors in selecting the correct tense for the context, and a tendency to learn regular past forms as individual lexical items. This suggests that there is a deficit in their knowledge of the syntactic requirements for tense marking and agreement. The subjects seem to compensate in part by relying to a greater extent on general learning and reasoning abilities, including memorization of regular inflected forms in a manner similar to the one in which non-impaired language learners are thought to learn irregular forms.