Within Teamwork Projects, you can impersonate other users on your site, meaning you will be using the site 'as' them, and you can see what access they have or make changes on their behalf.
Note: Only site administrators can impersonate users. You cannot impersonate another site administrator.
To impersonate someone, first go to the 'People' area of your site:
From the list of users, click the person you wish to impersonate, to view their profile. In the top right of that screen, you will see an 'Options' (three dots) button
When you choose the 'Impersonate' option you will see a bar in the bottom left of your screen to show you that you're impersonating them:
You can go to different areas in the site and view or edit items that would be available to that person.
You can use the 'Revert' link to stop impersonating them at any time.
Note: Any changes made while impersonating will be made to the account of the person you are impersonating.
For more information, see: Setting user permissions on a project