Biting Dog

How in the world do I get my puppy to stop biting me all the time? I have tried single words which he would be able to learn at one time being told and he thinks I am playing. He is a Great Pyrenees and huge for going on 4 months. He is still teething and I do have those hard treats and toys he can chew on but he prefers me.

[Aleda M Cheng, D.V.M., C.V.A]

He may not know that he is hurting you.  It is important to get him to understand that.  Puppies learn not to bite each other when they are siblings.  If one bites the other too hard the recipient will squeal and walk or run away, depriving the biter of a play companion.  You will have to find something that gets his attention when he bites such as your making a loud squeal (it doesn't have to be a word, try to imitate a puppy), or, shaking a can of pennies, or squirting him with a squirt bottle.  If these don't work put hot pepper sauce on your fingers or in the areas he bites most.  Once you get his attention with one of these devices, squeals, squirts, etc., than walk away.  Go into another room for several minutes.  You must also reward his good times.  If he goes 10 minutes with out biting give him a favorite treat.  Extend the time to 15 minutes after 2 days.  
This behavioral change will take some time and lots of persistence and consistency on your part.  Don't let your guard slip even once until the bad behavior is a thing of the past.

Additionally, he should go for professional training, if you haven