Personally, i think that whilst we are telling our youngsters what we 'shouldn't' or 'don't' 'do, it is too easy to forget that we don't actually tell them what we DO do....
You could try saying ' No, we don't hit/bite/shout etc. - we say i would like that toy please', or 'please can i have a turn on that ride....' But try not to give too long an explanation as your child won't remember it all - keep it simple. It may take a few tries - as it does take a while to introduce something new, as you will no doubt, already know.....and you may often have to remind him, but don't give up. Also, make sure you do get down to his level when talking and not just bending over to be put your face at his level - this can be intimidating. Good luck.