[puppylove]

I 100% agree with everything eyelovdogs said, I only have a couple things to add.....

Make sure that when the puppy has one of it's "accidents" in the house that you are cleaning the spot(s) with a good oder neutralizer right away, don't allow the poo/pee to dry.

In addition to praise you could maybe give a small treat while saying "Good boy"! The treats can be phased out as time goes, and just use the "Good boy" after that. I have a Dachshund mix, and most doxies are very hard to house train. I used this method plus what eyeluvdogs mentioned and she was trained in a matter of 2 weeks. I have heard that Chihuahua are also hard to train as well, even if they are a mix.

Are you crate training him? Keeping him in a crate or gated area w/ out carpet when you can't keep an eye on him every second. It's not advised to allow a puppy to have full range of the house until they are fully house trained.

It's allot like potty training a toddler. You just got to stick with it!

Good Luck!