Understanding Language is a resource tool from Stanford University, created as a PD tool for teachers with ELLs. One of the things teachers who complete the courses report is courses have prompted them to incorportate formative assessments with a language lens and involve students in process.
Citation: Rutherford-Quach, S., Kuo, A. C., & Hsieh, H. (2018). Understanding Their Language: Online Professional Development for Teachers of ELLs. American Educator, 42(3), 27.