Vocabulary and Input Quality Shape the Farsi Heritage Narrative Macrostructure in Farsi–English School-Aged Children

Abstract

Aims and Objectives: Narrative skills are essential for literacy and academic success and are shaped by linguistic knowledge and environmental factors such as input quantity and quality. This study compares narrative macrostructure skills in heritage Farsi–English bilingual children and examines the influence of internal (cognitive, linguistic) and external (input-related) factors. Design and Methodology: Thirty-seven Farsi–English bilingual children (mean age = 8;7) were assessed using LITMUS - MAIN for narrative macrostructure (Story Structure [SS], Story Complexity [SC]) and LITMUS-CLT for vocabulary in both languages. Internal and external factors were collected via parental questionnaires. Data and Analysis: Pearson correlation analyses examined associations among SS, SC, vocabulary measures, and internal and external background factors. Multiple regression analyses were used to assess the unique contributions of vocabulary and input-related variables to SS and SC in each language. Findings and Conclusions: Narrative macrostructure skills were comparable across Farsi and English. SS and SC were strongly correlated within each language. Vocabulary was associated with SS within each language but not across languages, and only English expressive vocabulary accounted for unique variance in English SS. SC was associated with vocabulary only in Farsi, suggesting a stronger role of lexical resources in supporting narrative complexity in the heritage language. Age at testing was positively associated with English SS, while age of bilingualism was associated with SS and SC in both languages. Richness of Farsi input was positively related to Farsi SS, whereas greater English use showed a negative association. Together, these findings highlight the role of vocabulary and input quality in narrative development, particularly in the heritage language. Originality: This study addresses an underexamined language pairing, Farsi–English, and demonstrates how linguistic and experiential factors jointly shape bilingual narrative development. Significance and Implications: The findings underscore the importance of assessing both languages and considering input quality when evaluating bilingual children’s narrative abilities, with implications for reducing misdiagnosis and supporting culturally responsive practices in clinical and educational settings.