How can you tell if your starter is going bad?

Usually it quits working outright or it works only every so many tries. However it can start dragging. A starter will draw a great deal of Amps when it is dying, Approx (300A) Mechanics have a simple gauge they lay on the cable that reads current (amps). Or just go to a parts dealer, they usually check this kind of stuff for free. . They can check your battery. And assuming your cables are good (the proper size) with all connections clean and tight it just may be the Starter. It is a process of elimination. If all else fails Replace the cheapest part first.