
Four months is still very young to expect perfection, and it's not the dog you train, it's yourself. You must learn to remember that he won't be able to hold on for much more than an hour at this age, and you must watch him like a hawk for signs that he is thinking about going. Circling and sniffing intently mean you have a few seconds at most to respond to the warning signals.
Don't just let him out alone to do whatever he needs to, go out with him and praise lavishly when he does a good thing, even maybe a signal word that you could always repeat at the appropriate time and he will connect the two. Mine all wee on command, I say 'get a wee wee' and they do!
So consentrate, and YOU'LL be perfect in no time. :)
Dawn R.