Honestly, I am no expert whatsoever since I've been trying to "train" my boy since he was 2.5 - that was back in January!! Anyways, I thought I'd try one last trick & if this didn't work then I would forget about it & he would have to tell me when this was going to finally happen.
I knew the "key" to stubborn kids finally doing the potty thing on their own was to find the right "trigger" - something that would motivate them enough to just get the job done. Since my kid LOVES to play with toys, I figured this was my best shot.
So I went to the local dollar store & bought up like $30 worth of small toys. Then I created the "potty prize box". This was last Saturday AM. I told him, "You go to the potty like we've shown you - on your own - & you can access the potty prize box." I let him look inside for a few seconds & then put it way up in the closet.
He immediately took his pants down & went to the potty. Then asked for a prize. A few hours later I asked him to use the potty - he did, got a prize. He had 1 accident that entire day. Prior to this little experiment he would go in the potty when we asked but it was ALWAYS a fight, lots of whining, screaming, etc.
Today will be Day #4 & we've had 2 accidents. He still doesn't initiate on his own, but it is a huge step for us that he willingly goes & STAYS DRY nearly the entire time. He even stayed dry over a 2-hr nap!!
The prizes have been less & less - I plan to narrow it down to 1 prize a day for awhile - if he stays dry the entire day. Then work it down to every other day, that sort of thing.
So my suggestion is to think about what your son LOVES, invest in a few of those & implement a potty prize system - he has to follow the rules to the "T" - meaning use the actual potty anytime he has to pee or poop. If he doesn't use the potty - no prize. See what happens!! Good luck!!
ETA: I also bought his favorite candy & will use that to get him to poop on the potty (which he's never done - he turned 3 in July). Once he's got the pee thing down on a regular basis then I plan to give him candy if he poops on the potty - for now we put a diaper on him since he won't sit yet.