My friend suggested that I buy a pair of bells to hang on our front door for my puppy to 'ring' with his paw when he tells us he needs to go outside.
Since we first brought him home we would take his paw and ring the bell just before we opened the door. It didn't take long before our guy figured it out for himself and so long as he's not busy (with a good bone or toy) he WILL ring his bell for potty use outside.
In my opinion, it beats barking or whining by the front door trying to tell me he needs to pee
Good luck!