
I foubnd that the best way to housetrain a pup was to watch it all the time it was awake. Whichever room I was in, so was the pup, and although I might be doing something else, one eye would always be on the puppy. Just as you wouldn't leave a crawling baby unattended and loose, the same with the puppy. If I had to go out, pup went in a playpen.
This way you learn to recognise the signs that he feels the need to go; little whimpers, sniffing the floor, circling an area, looking a bit agitated. This is the time you spring into action and cheerfully and excitedly call him out into the garden, and stay with him till he's performed (it may take a while for him to get back into the mood to go!), when you can give him lots of praise.
Housework generally gets done when pup's either asleep or someone else in 'on watch'. It's time-consuming and can be very boring, but it works.
:)