When you are in the house, keep him right with you with a leash on him tied around your waist or in a crate so he can’t wander off and find a potty place in the house. When you have him going potty outside reliably that way, then start letting him have a little free time in the house. Hang a bell on a string on the door at his level and teach him that when he bumps the bell, you will take him outside. When he puts 2 and 2 together and starts ringing the bell to tell you when he needs to go outside, he will be ready for more free time in the house. When he has gone about 4 months without pottying in the house, you can consider him potty trained, not until then.
