Scientific sensemaking, such as using data to reason and develop explanations about phenomena, is core to learning and doing science. Oral and written language, visual and numerical representations, physical models, and other forms of communication are vital to scientific sensemaking, yet research has not yet fully explored how science curricula can be customized to account for the unique communicative repertoires of individual learners within elementary science classes. This project will address this important gap in practice by developing a suite of tools that elementary teachers can use to customize existing open-source, standards-aligned science curricula, such that these curricula are better able to support students with a range of communicative strengths, including multilingualism. Specifically, the project team will partner with elementary educators to co-develop customization tools to accompany peer-reviewed, open-source science education curricula. These customization tools will serve as the basis for professional learning modules on how to support learners who speak one or more languages, in developing and using their full communicative repertoires while engaging in scientific sensemaking, as guided by the curricula. Subsequent research will explore whether and how the professional learning experiences influence participating teachers' beliefs, preparedness, instructional practice and curricular customizations. The resulting empirically based professional learning