Do you think he can hold it for a few hours? And maybe knows when it's coming?
I found the princess polly potty book great for mine there is a boy equivalent, so that he starts thinking about what he should be doing.
I d then be tempted by a week at home to devote to it and make a big deal about big boy pants in the run up to it and then go for big boy pants no trousers. I know that's not easy with other children in the house but as far as you can just clear the diary.
Neither of mine responded to pull ups or trainer pants they would be happy to stay in a wet or dirty one all day if I d let them!
You ll have a few days of wet puddles then fingers crossed he ll get it, if not back to nappies.
Ours always started themselves early did really well and then regressed
I hate potty training you have my complete sympathy!
Good luck