This article provides information to educational leaders about how to address the challenge of supporting students who are emergent multilingual--i.e., those identified as English Learners (ELs) by their schools--in middle grades mathematics classes. The ideas in this article draw on research and collaborations with hundreds of teachers across the country. The article describes the role that mathematical diagrams can play in providing access to mathematical learning opportunities and facilitating participation in mathematical communication for students who are ELs. Three examples of what EL student diagram use can look like are provided to demonstrate benefits of supporting diagram use for students, as well as benefits for teachers who can then have a better understanding of what their students who are ELs are understanding and communicating. Strategies for supporting this kind of diagram use in the classroom are also explained, with an emphasis on ensuring that ELs are fully engaged in mathematical problem-solving and in classroom mathematical discourse. [This article was published in "Educational Leadership" (EJ1236932).]