Select the Gradebook tool from the Tool Menu of your site.
Grades and comments originating from sources other than the Gradebook (e.g., Assignments or Tests & Quizzes) will display with icons. Clicking on the icon will confirm the origin of the item.
Note: While grader comments will appear in the Gradebook for items such as assignments and quizzes, remember that additional instructor feedback and/or graded file attachments may also be available via the Assignments and Tests & Quizzes tools.