Like everyone else is saying Duke needs to be on a schedule...pick 2 times a day to feed him (unless you only feed once a day), early morning and in the evening for example. Keep to that Schedule. He also needs to be crated if you can, i couldn't imagine house training a dog without a crate, it makes the whole process a whole lot easier...When hes done eating he needs to go out, when he gets up from a nap he should go out aswell.