In this article, the authors describe how their NPD project aims to support bilingual classroom teachers' understanding and implementation of translanguaging as theory and practice. They share two practical tools they developed to help teachers approach formative assessment through a translanguaging lens. The first tool is a classroom conversation observation tool that equips teachers to capture what focal students can do in conversations about grade level content in Spanish, English, and via translanguaging. Tool 1 is aligned with the Common Core Speaking and Listening standards and includes a blank template teachers can use to align the tool with relevant standards across content areas and grade levels. The second tool is designed to help teachers (1) get to know a student as a holistic individual, (2) use that information to identify high-interest books for the student, and (3) employ culturally and linguistically responsive adaptations, such as translanguaging, to formatively assess the student's reading. Both tools are intended to guide instruction via informal formative assessment: Identifying students' strengths and needs helps distinguish aspects of language and literacy necessary for future instruction.