Professor Jeannette Mancilla-Martinez focuses her research on one of the most timely and consequential challenges in American schooling—the education of English Language Learners. Her careful longitudinal studies of children’s language from early preschool through the middle grades have been informed by sophisticated analytical tools designed to describe their language development in ways that capture the nuances of acquisition in both Spanish and English, and take into consideration learning opportunities in school and home contexts. Professor Mancilla-Martinez is now applying that research in building interventions that use language learning as a pedagogical catalyst to support students’ achievement in mathematics and reading.