Student want to chat with classmates
Can my students message each other? If so, where do I find instruction on how to?
Yes. You can post messages on the activity stream/profile of a person. I will post on yours to give you an idea of how it works.
They can visit each other's profiles by clicking on their classmate's username. From there, they can post on their friend's activity stream. They can also block each other from doing so, and you can disable their ability to communicate via Duolingo in your Duolingo for Schools settings. :]