L.S.
Honestly, if he can't let you know he needs to go, whether verbally or another way, then he's probably not ready to potty train. I'd wait a few more months.
Some signs that he IS ready are:
-telling you he has to go
-asking to have his diaper changed after he goes
-being able to pull his pants up and down
-staying dry for his naps or a few hours at a time
If you start to train before he's really ready, you're going to be frustrated because it's going to take SO much longer than if you wait till he is ready. Typically for boys, anywhere between 3-4 is pretty normal.