How do I leave comments for students in the Gradebook?
If you want to leave simple feedback for your students, you can leave a text comment directly from the Gradebook.
Learn how students view assignment comments in the submission details page.
Note: You can also grade assignments from the comments window in the Gradebook. However, you cannot add a comment and assign a grade at the same time.
Where there is more than one comment for an assignment, comments will be listed in chronological order with the oldest comments appearing at the top and the newer comments appearing near the bottom .
Note: If you need to remove a comment, click the More Details in the SpeedGrader link  to view the assignment in SpeedGrader.