I agree with the others, just do a quick arhh arhh (assume thats how it is written without sounding like a pirate

) when doing something unacceptable. It can be down to the tone of your voice that winds a puppy or dog up.
I find that shorter words spoken in a deeper tone means what I am asking. Jinley is going through adolescence and thinks she can go back to the car after a walk without her lead on. And if she doesn't think she has walked enough just stands and stares at me about 10foot away!!

If my OH (who has done no training with her) says stay to have her lead on - she does

so I say it now in a more authoritative voice and she listens.
At the age of Doogle he needs to be encouraged to change his behaviour, not just by telling him to stop doing something, but to follow it with a friendly command of what you want him to do. For example if say he is chewing your slipper and he growls when you try to take it off him, I would just say arhh arhh, then walk away slightly and in a chirpy voice say "come" then "sit" then give him a treat when he has done this.
He will associate the treat with come and sit rather than exchanging for the slipper.
It worked for me, others will have better ideas. But your puppy isn't being naughty he is just learning and probably playing with you the same as he did with his littermates.
Hope this helps.
Pat