Is there a way to tell which questions I have finished?
Yes. At any time you can go to the Navigation Bar at the top of the screen and select the "Validate, Certify, and Release" link. The system will then display all remaining errors and warnings listed by section and question that must be satisfied before you can submit the form. In order to navigate to any sections listed as having issues, use the "section" navigation bar at the top of the screen.