The biliteracy unit framework (BUF) for teaching for biliteracy organizes the two languages strategically to avoid flip-flopping and concurrent translation. While a unit spans three linguistic spaces, the only time Spanish and English are used together is during the Bridge. During Spanish time, the teacher uses comprehensible strategies so that all students develop language and learn content in Spanish, and during English time, the teacher uses comprehensible strategies in English that teach both language and content.