Differentiate between contexts that call for formal English (e.g., presenting ideas) and situations where informal discourse is appropriate (e.g., small-group discussion).

This standard calls for more of the code-switching that we were talking about in the Common Core Standards for Speaking and Listening. Differentiating between formal and informal language is a necessity. It's a good idea to explicitly discuss the differences, but your students will probably get a feel for them intuitively. Then remind them throughout the year when formal language is expected. Don't stress too much—this is a pretty standard standard.