An increasing focus on academic language across content areas, including science, prompted this study of the ways in which preservice teachers integrate academic language in middle grades science. Academic language is part of the discourse that students need for success in school, and it includes both what words are used and how those words are used. Three preservice teachers, all enrolled in an applied linguistics course for an English for Speakers of Other Languages endorsement, were part of this case study. Through content analysis, we explored how they incorporated academic language into middle grades science units on thermal energy, Newton's laws of motion, and the classification of living things. Findings indicated that each preservice teacher selected language functions to complement and extend middle school students' understanding of scientific content concepts. In other words, science concepts drove their integration of academic language and informed their evaluation of the success of their teaching those concepts.