Much attention is now given to academic language, particularly in content areas such as science, amid persistent achievement disparities between students classified as English Language Learners, and more recently, Long Term English Learners, and their English-proficient peers. This attention has fueled debate about the precise features of such language and the best ways to help students develop them. This work uses data from ethnographic observation and recordings of student interactions of a fifth grade cohort in a bilingual education program to show that by allowing students ample use of their full bilingual repertoires, extensive collaboration, and authentic experience and exposure to target language varieties, they are supported in their learning of new content and linguistic forms. The paper argues for a translanguaging perspective to teaching, whereby language and language acquisition are framed as social meaning-making processes and standardized forms are questioned, such that students can leverage familiar communicative practices and develop a critical awareness of target discourses including the so-called language of science. The paper closes with a precaution about oversimplifying translanguaging pedagogies to a linguistic free-for-all, stressing the importance of authentic input in target forms if these are expected outcomes.