My rescue dog is not getting it on potty training?

I adopted a rescue Chi/Jack Russel mix who is between a year and two years old. I've potty trained dogs before and I'm home all the time but my new dog is not getting the concept. I use praise and treats when he does well but most of the time when I take him out to my yard he does nothing. I leave him in a corral at night which works and actually leash him to my chair while watching TV but he'll still pee right in front of me. I'm worried that he is not going to get it and I'll have to return him.