Sentence imitation as a tool in identifying expressive morphosyntactic difficulties in children with severe speech difficulties

Abstract

Sentence imitation has been identified as a good indicator of children's language skills, with performance differentiating children with specific language impairment and showing relationships with other language measures. It has a number of advantages over other methods of assessment. The assessment of morphosyntax in children who have severe speech difficulties presents unique challenges which currently available sentence imitation assessments do not address. This paper presents a new sentence imitation test (The Sentence Imitation Test (SIT-61)) and reports on an investigation which sets out to determine whether this test (1) reveals differences in performance between a group of children diagnosed with specific language impairment and a group of typically developing children (2) reveals distinct profiles of performance amongst children with different speech difficulties, and (3) provides information about morphosyntactic strengths and difficulties. SIT-61 is a finely graded sentence imitation test in which the phonotactic structure, segmental phonology and length of words were kept as developmentally simple as possible. Responses are scored for number of content words, function words and inflections correct. A novel scoring system was devised to credit a child where there was evidence of targeting a morpheme even if it was mispronounced. The test was administered to four groups of children between the ages of 4 and 6 years: 33 children with typical development, 13 children with known expressive morphosyntactic difficulties (specific language impairment), and two groups of 14 children with different types of speech disorder: a group with consistent phonological disorder, who used atypical phonological error patterns consistently; and a group with inconsistent phonological disorder, who produced atypical phonological errors inconsistently. SIT-61 found differences in performance between the group of typically developing participants and the three clinic groups. While the consistent phonological disorder group obtained extremely high scores for content and function words, they obtained lower inflection scores reflective of their speech difficulties. The scores of the specific language impairment and inconsistent phonological disorder groups were comparable for content and function words, but the groups were differentiated through an analysis of their errors. Further analyses confirmed that low scores obtained by some children in the inconsistent phonological disorder group were due to morphosyntactic difficulties and not speech difficulties. A new sentence imitation test, the SIT-61, is shown to be valuable tool for identifying expressive morphosyntactic difficulties in children. It is informative about the morphosyntactic abilities of children with speech disorders and raises questions as to the nature of their difficulties.