Yes. Clutch slip manifests itself in initially in high gears at peak torque when the clutch is under peak load. You can usually initiate slip when the clutch is on the way out by doing a fast shift into third gear at maybe 2500-3000 rpm and go WOT as soon as the clutch is engaged. At higher rpm in lower gears they generally hold ok but at peak torque in higher gears at lower engine speeds they let go. If you keep your foot into it when it slips it will hook up again as the clutch temp rises. When it's really worn it just wont hook up again under those conditions. If you nurse it you can probably get quite a few more miles out of it.
Ciao
