At 5.5 months puppy should be able to hold it overnight.

Make sure all inside surfaces are disinfected and most importantly deorderized. Else puppy will smell the urine, and continuously go in the same place- crate or some other favorite place in the house.

No water after 8 pm to avoid night accidents, until he proves to you that he can hold it. Assuming dog is inside in airconditioning during the summer.

If you catch puppy in the act- read the riot act to him. Yell and be vocal, crack a newspaper against your hand for sound. Keep scolding as you clean it up. Again don't forget the deordorization!

If you take puppy outside and it does a wee wee- tell it "good puppy wee wee, good wee wee". Act like the dog just won the lottery! With mine I now tell them "make a puppy wee wee- right there", and they actually do it-right there. So puppy will pick up on the words if used as a reinforcement.

My older female (2.25 yrs) lets me know by "panting". She knows if she puddles inside I'm going to yell at her- so she gets nervous, and stands in front of me panting. My male (almost 2 yrs) will run to the door back and forth, and if I haven't caught on will nudge me with his head on my lap. Actually the female sometimes mimics this behavior- they learn from each other. Finally if that fails he does the logical- sneaks off and does it on the bathroom floor. By then I'm at fault, and even if I point it out to him, he'll just stand and wag his tail.

Until you can trust him, don't let him out of your sight in the house. Keep going out each hr or as much as possible. In fact if puppy is due for a wee wee, don't bring him back in until he does. Dogs always seems to have a full tank for scent marking.