When you’re reviewing a student submission, you’ll see "Comments" on the left hand side under the student name.

Click on it to leave a message for your student. Once you return their work, they will be able to see your comment.

There is also a toolbar at the top of the Review Submission page that has a pencil you can use to mark up your students work!

You can even add stickers to your student’s submissions by clicking on the star button.

You can also comment anywhere on a student’s submission by clicking on the 'Add Text' button on your toolbar. Draw your text box and write a comment to your student on the notepad.