Identifying Caregiver Behaviors that Promote Spanish Development in Preschool-aged Emergent Bilinguals at Risk for Developmental Language Disorder - PROJECT SUMMARY/ABSTRACT Emergent Bilingual (EB) children of Spanish-dominant caregivers represent a large and growing proportion of the school-aged United States population. For EBs, developing proficiency in the language used by caregivers at home is foundational to supportive family relationships and later school outcomes, yet research has shown declines in EBs’ home language proficiency after school entry (Castilla-Earls et al., 2019; Jackson et al., 2014). A particularly vulnerable subset of EBs are those with Developmental Language Disorder (DLD), which is characterized by low language skills despite otherwise normal development and occurs in about 7% of children. Given the scarcity of bilingual service providers, caregiver-delivered language interventions are a practical and promising approach to preventing and treating DLD in the home language. Yet little is known about the specific caregiver behaviors that sustain home language development in EBs with or at-risk for DLD in preschool (age 3-5), a period when overall exposure to English increases. This project addresses this critical gap while supporting the candidate’s transition to independence through training in child language disorders, parenting interventions, and novel approaches to using bilingual daylong recordings. By leveraging observational language data from two large-scale randomized clinical trials (RCTs) of a parent-coaching program called Play and Learning Strategies (PALS; Landry et al., 2008) the current project will identify caregiver behaviors specific to bilingual contexts that contribute to preschool-aged EBs’ home language use and skills. During the mentored K99 phase, using existing data from a completed RCT, Aim 1 will determine the impact of PALS on targeted caregiver behaviors (e.g., contingent responsiveness) and child Spanish outcomes with the subset of parents who received coaching in Spanish (T=71, C=70). Aim 2 will recode video observations from this dataset to identify home-language supportive behaviors (e.g., caregivers Spanish use, responses to child English use) that predict children’s later Spanish proficiency (n=141). Next, new daylong recordings (n=160) will be collected alongside an ongoing PALS RCT tailored for Spanish-English EBs at risk for DLD (risk determined via Spanish and English language screeners at preschool entry). During the independent R00 phase, Aim 3 will determine 1) whether home-language supportive behaviors captured in daylong recordings predict child Spanish outcomes and 2) whether PALS coaching leads to changes in these behaviors, which in turn explain child Spanish outcomes. By capturing spontaneous language-rich interactions that occur throughout the day with different conversation partners in the context of a larger ongoing RCT, this project promises to generate new insights into the conditions and caregiver behaviors that support bilingual development in EBs with DLD and inform culturally and linguistically-sustaining interventions. This award also provides critical training that builds on the candidate’s background in bilingual language development and positions her to launch an independent research program focused on the intersection of bilingualism and language difficulties in preschool-aged children.