The Impact of Age of Acquisition on Cross-Linguistic Influence in Children’s Linguistic Competence

Abstract

Bilingual language development is shaped by multiple factors, among which age of acquisition (AOA), crosslinguistic influence (CLI), and linguistic competence play central roles. AOA determines whether a child acquires two languages simultaneously or sequentially, with earlier exposure often associated with more native-like proficiency, while later exposure tends to strengthen CLI. CLI is a natural and systematic process that reflects the interaction between two languages. It can extend beyond target-like forms to include ungrammatical or pragmatically inappropriate structures. Linguistic competence, particularly in syntax and semantics, both shapes and predicts the degree of CLI, demonstrating its importance in understanding bilingual development. Current studies reveal that CLI is universal, and its form and intensity vary according to timing of exposure, type of structure, and input quality. However, much of the existing research is limited by small sample sizes, homogeneous participant backgrounds, underrepresentation of sequential bilinguals, and a lack of longitudinal designs. Future research should adopt larger and more diverse samples, include control groups, and make greater use of longitudinal approaches to better capture developmental patterns. Expanding the scope to less studied areas such as pragmatics, phonology, and discourse will further enrich the understanding of bilingual development.