Marco has no such feature (searched in gsetting keys and shortcuts config). You can see the active workspace on the pager applet . If you don’t have the applet on the panel you could call the window menu e.g. right click on the titlebar or alt+space (by default) then select “move to a diffirent workspace” and in that list the active workspace will be grayed out since you can’t move the window to the same workspace you are on. Another solution is to use Compiz .