your post is vague....

if starter grinds....replace starter, inspect flywheel (flywheel should be ok).

if your car doesnt crank at all.......look at the fuse end link that is on the starter. sometimes those are a loose connection.

i dont know exactly why a starter would grind...like the mechanic side of it....but if it does grind...the starter is bad...unless your flywheel has no teeth for the starter to grab...but that is really far fetched and unlikely