My dog seems aggrasive

[Lovesanimals]

Well his kinda getting the sit thing

[Giselle]

Yikes! This 7 year old pup doesnt know sit? Poor thing..

I'll have to agree with LilacDragon in this case. Instead of negative reinforcement, work on convincing the dog to "Give". Use the method described in LilacDragon's post. Give a regular biscut to the dog. Say "GIVE" and hand the dog a yummier better treat. As soon as he takes the yummier better treat, quickly take the regular biscuit. Repeat this with toys and other treats. As soon as he gets the idea, DON'T treat everytime. You want to use the benefit of "jackpotting". Eventually, your dog will give up whatever he's chewing if you go about this the right way.

Have you any previous experience training dogs? If not, I would suggest you attend your local shelter's obedience classes. The place where you adopted this dog should hold them for discounted prices. Also, advise them that your dog may be developing food aggression so they can help you with that.