Efforts to improve educational outcomes for English learners often focus on "academic language," but unfortunately the field lacks a clear, agreed-upon definition of the concept. This article reports on a design research study that focused on students' engagement in one academic practice over several months: reading and discussing expository science texts in Spanish. By looking closely at one practice, the research provides a grounded perspective on academic language and the bilingual resources that English learners bring to academic tasks. (Contains 1 table and 3 footnotes.)