I cant turn the key any advice on what it may be??

 

Tap the head of the key with a little hammer.

 

^^^^^^
that and spray some Lock lube into the key cylinder. If Lock lube is not avalible, just use WD-40

 

and if that doesn't work, you'll probably need to replace the cylinder.

 

How many miles are on the car? Usually when I see cars with 180K+ the actual key itself wears first and the part that goes in the igintion is all rounded off to like bumps on the key.
Usually if you pull the key out a hair and then turn it it works.