This book explores multilingual practices such as translanguaging, code-switching and stylization in secondary classrooms in Hawai'i. Using linguistic ethnography, it investigates how students in a linguistically diverse class, including those who speak less commonly taught languages, deal with learning tasks and the social life of the class when using these languages alongside English as a lingua franca. It discusses implications for teachers, from balancing student needs in lesson planning and instruction to classroom management, where the language use of one individual or group can create challenges of understanding, participation or deficit identity positionings for another. The book argues that students must not only be allowed to flex their whole language repertoires to learn and communicate but also be aware of how to build bridges across differences in individual repertoires. It offers suggestions for teachers to consider within their own contexts, highlighting the need for teacher autonomy to cultivate the classroom community's critical language awareness and create conducive environments for learning. This book will appeal to postgraduate students, researchers and academics working in the fields of sociolinguistics and linguistic ethnography as well as pre-service and in-service teachers in linguistically diverse secondary school contexts.