If you'd like to have students be able to communicate about assignments outside of class, or respond to and discuss a question you provide, there are two simple and commonly-used tools you can try.
For School Loop users, there is a
Post Discussion/Blog option that accompanies every assignment, which teachers can initiate, or which any student in a class can start (teachers are part of the thread, too). This can be a great way for students to support each other by answering each other's questions or providing clarity on an assignment. Teachers can also ask a question and require students to reply either to the question or to other students' answers. All posts happen under students' real name, so attribution is not an issue.
You can also start a discussion for a group, rather than through an assignment, from the Groups page in School Loop.
Teachers who prefer to use Google Classroom also have the
"question" option under the Classwork tab. This can be a graded or ungraded assignment. Students can simply respond to the question, or you can allow them to reply to each other and start threads as part of the discussion. As with the School Loop option, students' real names are listed.