PROJECT SUMMARY Children with a developmental language disorder (DLD) are roughly five times more likely to struggle with reading when they reach school age than a child without language issues. Given the frequent co-occurrence of language and reading disorders, early identification of children with DLD is critical for mitigating long-term risk in reading. This is particularly important for bilinguals (English learners/dual language learners). One in 5 children in the U.S. begins school speaking a language other than English; however, there is a stark shortage of diagnostic screening tools that can be administered with young bilingual children to identify language and possible concomitant reading disorders. The proposed project will develop and pilot a novel sentence repetition task for the differential diagnosis of DLD and/or dyslexia in bilinguals. Sentence repetition taxes both grammatical ability and phonological processing ability—two areas commonly affected in language and reading disorders, respectively. Deficits in sentence repetition performance have been reported among children with DLD (Archibald & Joanisse, 2009), dyslexia (Moll et al., 2015), and concomitant DLD+dyslexia (Bishop et al., 2009). Critically, sentence repetition has also shown high levels of specificity and sensitivity when used to identify disorders in bilingual children (Pratt, Peña, & Bedore, 2020), who are still in the process of developing their grammatical and phonological representations. In year 1, the Principal Investigator will develop an initial set of 48 sentence repetition items in English and Spanish (24 per language) that systematically vary in their inclusion of grammatical and phonological targets. In years 1-2, 150 school-age Spanish-English bilingual children in Southern California will be recruited. Based on clinical referral and children’s performance on reference measures of language and reading ability, participants will be accrued into diagnostic groups: bilinguals with DLD (n=25), bilinguals with dyslexia (n=25), and bilinguals with comorbid DLD+dyslexia (n=25). Bilingual children who do not fit a diagnostic group will serve as typical language and reading controls (expected n=75). The novel sentence repetition task will be administered to all participants. Participants will also complete a brief supplemental battery of phonological processing tasks, to explore linguistic and phonological predictors of performance. Pilot data will guide an iterative process of culling and revising test items. Person-item leaf plots, as well as information function, will examine the distribution of correct responses across diagnostic groups. Concurrent validity will be evaluated by examining the correlations between sentence repetition and the reference measures. Predictive validity will be evaluated in year 3.