This study examines whether and how tapping into students' everyday language in a web-based learning environment can improve all students' science learning in linguistically heterogeneous classrooms. A total of 220 fifth-grade English Language Learners (ELLs) and their non-ELL peers were assigned to either an everyday English approach condition or a textbook approach condition, and completed technology-enhanced instruction focusing on respiration and photosynthesis. Students in the everyday English approach condition were taught the concepts in everyday, conversational English before content-specific scientific terms were introduced, while students in the textbook approach condition were taught the same concepts and vocabulary simultaneously. The results show that the everyday English approach was significantly more effective in helping both ELLs and non-ELL students develop a coherent understanding of abstract concepts related to photosynthesis and respiration. Students in the everyday English approach condition were also better able to link content-specific terms to their understanding of the concepts. These findings show the potential advantage of using students' everyday English as a resource to make science more accessible to linguistically diverse students in mainstream classrooms. By integrating students' everyday language in science instruction, it is possible for all students including ELLs to acquire both the content and language of science.