Core vocabulary in the narratives of bilingual children with and without language impairment

Purpose: Children with primary language impairment (PLI) demonstrate deficits in morphosyntax and vocabulary. We studied how these deficits may manifest in the core vocabulary use of bilingual children with PLI. Method: Thirty bilingual children with and without PLI who were matched pairwise (experimental group) narrated two Spanish and two English stories in kindergarten and first grade. Core vocabulary was derived from the 30 most frequently used words in the stories of 65 and 37 typically developing (TD) first graders (normative group) for Spanish and English, respectively. The number of words each child in the experimental group produced out of the 30 identified core vocabulary words and frequency of each of the core words produced each year were analysed. Result: Children with PLI produced fewer core vocabulary words compared to their TD peers after controlling for total words produced. This difference was more pronounced in first grade. They produced core vocabulary words less frequently in kindergarten than their TD peers. Both groups produced core vocabulary words more frequently in English than Spanish. Conclusions: Bilingual children with PLI demonstrate a less productive core vocabulary use compared to their TD peers in both their languages illustrating the nature of their grammatical and lexical-semantic deficits.