Students sometimes ask why English Language Arts teachers spend so much time on grammar. Here are a few prompts to lay the ground work for such instruction. Once students understand why it may be to their advantage to be able to switch to Standard English, they often are more open to learning and practicing this form of English.
Caution: Please honor the way students talk as long as it’s respectful of others. When we honor our students, they trust us and remain open to learning.
Why teach/learn Standard English? Where have students observed this behavior in their own community and circles of friends? When is advantageous to the speaker to use a different language, dialect or version of English?
See article from Teaching Tolerance
Carefully select the video clips that will work in your setting. NPR article on code-switchng
Also see Chapter 3 “Exploring Traditional and Contemporary Grammars” in Teaching Middle School Language Arts: Incorporating Twenty-First Century Literacies (2010)