Developmental Patterns of Intrasentential Code-Switching in Spanish-English Bilingual Children Ages 4-8

This study investigates developmental trajectories of intrasentential code-switching rates in Spanish-English bilingual children within the context of developmental psycholinguistics and bilingualism research, an area of growing scientific importance given its implications for dual-language program design, bilingual assessment practices, and language intervention planning for bilingual children. Using naturalistic conversational corpus collection in home and school settings plus picture-naming experimental tasks, we examine lexical access competition between languages resolving via higher-frequency or lower-effort lemma retrieval across languages in 216 Spanish-English bilingual children ages 4-8 and 48 adult balanced bilingual comparators drawn from dual-language preschool and elementary school programs in Los Angeles County. Results indicate that code-switching rates decline significantly from ages 4-6 (mean 31.4 switches per 100 utterances) to ages 6-8 (18.2 per 100) in dominant-English children but remain stable in balanced bilinguals, with school context suppressing switches by 42% versus home context (p < 0.001), with 42% switch suppression in school vs home context as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to developmental psycholinguistics and bilingualism research and carry actionable implications for the design of programs and policies targeting dual-language program design, bilingual assessment practices, and language intervention planning for bilingual children.