well id say if it starts slipping when you take off, or maybe not slipping as much as a chatter like feeling , or if you are really getting on it it can slip and you will smell burnt clutch.
yes, clutches do ware just like brakes, and they also have top be replaced, but usually folks will get way over 100,000 before that happens. On today's clutches there are hydrolic slave cylinders that will also go bad, this is usually a bad thing and will usually act like the clutch is gone out, and as bad as it is usually when you have the slave cylinder replaced you might as well go and have the clutch replaced as well since they are already in the same area.
