LAUSR

Children with autism spectrum disorder (ASD) have varying degrees of language impairment across multiple domains, which may include deficits in syntactic, pragmatic, and/or semantic skills. The heterogeneity of language profiles within ASD, coupled with the limited scope of existing standardized language measures, makes a comprehensive assessment of language impairments in ASD challenging. The Observation of Spontaneous Expressive Language (OSEL) is a new measure developed to capture children's spontaneous use of language in a naturalistic setting. The current study used the OSEL to examine the patterns of spontaneous expressive language abilities of 87 clinically ascertained children with ASD from 2 to 12 years. As expected, children with ASD were significantly more impaired in their spontaneous use of language compared to typically developing peers. Syntax and narrative skills continued to increase with age from toddler to elementary school years in cross‐sectional comparisons. Pragmatic skills improved form toddler to preschool years but remained stable from preschool to elementary school years. Preliminary data also demonstrated significant improvements in OSEL syntax scores over time for a subset of children followed longitudinally (n = 8). Children with ASD consistently showed more impairments in spontaneous expressive language captured on the OSEL compared to language skills measured by other more structured standardized assessments, despite moderate convergent validity among those measures. Results suggest that impairments in the spontaneous and functional use of expressive language persist into middle childhood for many children with ASD, and a comprehensive assessment approach can lead to more precisely targeted treatment addressing specific language profiles.