I don't know what the thing in the middle that spins to wash and scrub the clothes, but that part will not spin to wash the clothes any more can any one help me with this. I can do the repair I just need to know what's wrong

It's an agitator. Does it turn when you move it by hand?
Whirlpools have things called dogs in the agitator. Depending on your model, it might go like this

Remove the top of the agitator.
Pull out the plastic cap - don't break the O-ring.
Remove the head bolt.
Lift the agitator out. This may or may not take the strength of Hercules.
Hold it down on the floor with your feet and separate the two halves with your hands.
6. The agitator dogs should be visible in the top of the bottom half of the agitator.
They are very cheap to replace (Sears, etc)
To reinstall, hold the agitator halves sideways with one hand inside the bottom part to keep the dogs in their grooves.
Slide everything together carefully. They will still move freely. When you have the two agitator pieces together, you can turn the top agitator and notice that it will go one way.

And if you find socks stuck under it consider buying a mesh bag to wash those small things in.

There is a hub made of placstic that wears out. Its located under the agitator. Pull straight up on the agitator inside the drum. The is a white cap looking piecewith a bolt in the top. If it turns by hand it needs replaced. Loosen the. Bolt in the top and pull straight up. Real cheap to replace. Clean up the shaft with a rag before you place the new one. The agitator just clips back onto the cap or cup. I can't remember the technical name of the part right now. But that's what it looks like. Joy is right also depending on what model u have. Good luck.