PROJECT SUMMARY/ABSTRACT Code-switching (alternation between language in a single utterance) is a common phenomenon observed among bilingual children with typical and atypical language, including children with developmental language disorder (DLD). Code-switching requires the speaker to integrate morphosyntactic features in both languages; therefore, language proficiency and social factors are important factors to consider when analyzing code- switching patterns. Current research on code-switching in children with DLD is limited by methodological issues, including problems with coding approaches, elicitation tasks, and accounting for children's language development. To address these issues, this proposed study will use a comprehensive coding method and a conversational elicitation task to examine code-switching patterns in bilingual children with and without DLD. The study will consider two perspectives, linguistic and sociolinguistic, to understand how language ability interacts with this phenomenon. The study will involve a Diapix task with three different interlocutors (English- only, Spanish-only, and bilingual Spanish-English). The conversations will be recorded, transcribed, and coded. This study aligns with the National Institute of Health's (NIH) vision and mission statement of seeking fundamental knowledge to advance diagnostic practices for clinicians working with bilingual Spanish-English speaking children globally. Ultimately, this project aims to provide essential and innovative research in the area of bilingual language disorder, while also training a promising new investigator in ethical, methodological, and substantive research practices.