Insights into the morphological errors of adolescents with ASD

This study examined the morphological abilities of Hebrew-speaking adolescents with autism spectrum disorder (ASD), compared to typically developing (TD) peers. While prior research has reported variable language outcomes in ASD, few studies have analyzed the nature and source of morphological errors, particularly in morphologically rich languages such as Hebrew. Fifty-three adolescents (28 ASD, 25 TD), matched on age and gender, completed tasks assessing noun pluralization, verb inflection, and agreement structures. Errors were categorized into three domains: morphological (e.g. rule-based inflection), lexical morpho-phonological (e.g. irregular form), and morpho-syntactic (e.g. agreement integration). Group level analyses revealed similar performance in noun pluralization, plural agreement, and future tense tasks. Additionally, marginally significant group differences in the past tense task and significant group differences in the mixed-tense task were evident, with the ASD group showing lower accuracy in both cases, reflecting greater difficulty in integrating temporal and morpho-syntactic features under conditions of multiple morphological alternations. Within-group analyses showed that tense was the most error prone feature. Individual level comparisons identified 13 ASD participants with elevated error rates, showing either selective or cross domain impairments. Their profiles were consistent with the group-level pattern, indicating that difficulties in ASD were concentrated in linguistic processing conditions characterized by greater complexity and higher processing demands. These findings highlight the value of a typological approach to error analysis and underscore the heterogeneity of linguistic abilities in ASD. They emphasize the need for detailed assessment and individualized intervention, particularly in morphologically complex languages.