Although many English language learners (ELLs) in the United States have knowledge gaps that make it hard for them to master high-level content and skills, ELLs also often have background knowledge relevant to school learning that teachers neglect to access, this author argues. In the Common Core era, with ELLs being the fastest growing population in U.S. schools, teachers must learn how to recognize ELLs' previous knowledge--including literacy learning in their native language--as an intellectual resource. Such knowledge can become a bridge to learning new content. Dong describes how she guides pre-service teachers in her graduate courses to assess non-native English speaking students' prior academic knowledge and skills, and to integrate both this prior knowledge and culturally relevant examples into lessons to make learning more meaningful for ELLs. She gives three examples of how pre-service teachers who tutored an ELL modified their lessons--in social studies, math, and science--to tap into the students' prior knowledge and home cultures.