When i turn the key on my 2002 ford focus it just humms what's that?

When i turn the key on my 2002 ford focus it just humms what's that?

You need to remove the starter motor and make sure the small pinion moves on the shaft, if not use WD40 spray to free it off.
while it, s out check the teeth on the starter ring inside the engine if it, s badly worn the engine will have to be removed to replace it. But hopfully it, s not that!

If you hear a humming sound coming from the rear of the car when you turn the key to the 'on' position, that's just the fuel pump priming itself and is a normal sound to hear.

Bad solenoid on your starter.