Impaired use of function words in European French-speaking children with developmental language disorder

Function word (FW) is a reliable marker of Developmental Language Disorder (DLD), yet their profile in European French (EF) preschoolers remains poorly understood. This corpus study compared FW use in 73 monolingual EF-speaking children with DLD (39-84 months, M = 54, SD = 10.93) and 76 typically developing peers (24-36 months, M = 30, SD = 5.97) matched on mean length of utterance in words (M = 2.5). Six FW categories-articles, prepositions, demonstrative pronouns, subject pronouns, and modal and auxiliary verbs-were analysed using chi-square tests and log-linear regression. Performance was comparable for articles and prepositions, but children with DLD showed impairments of FW use related to verbal contexts-reduced pronoun use, skewed FW distribution, and frequent omission or agreement errors with modal and auxiliary verbs. These patterns indicate processing limitations beyond developmental variability, implicating working memory, procedural learning, and sensitivity to input regularities. The findings refine cross-linguistic models of DLD and highlight FW assessment as a sensitive diagnostic tool for EF-speaking children.