Need to know if he has constipation issues or eating issues- it is relevant :)

Special rewards can work especially if the child loves something in particular most of all. Then you can say that when he goes to potty successfully, he will get a "new Thomas train" or whatever he is into. This worked like a charm since he couldn't wait to get another new train! But, this can get expensive over time. Eventually, you can eliminate it when he's mastered the potty. You can then change this reward to be for another challenging behavior he is working on.

Also the suggestion of reading a book that stays in the bathroom worked out well for us too. He liked to read "The Potty Book" about what to do when he goes. It was published by one of the diaper companies I think. And he had a special car that you pull back and let go and he would send it across the floor to me and I would send it back to him. He liked doing this, but it wasn't until he could earn a new train that he really started using the potty successfully.

Don't rush him and be patient. Sit with him while he is there and talk to him about something fun. Sometimes it's just a matter of being patient until he is ready.

It helps to catch her/him consistently. When there are any clues he/she needs to go or are, Say something like "time to go to the bathroom" and bring her/him to the bathroom and provide them with what ever else assistance they need. Also maybe schedule bathroom breaks with what ever consistency you find needed to further encourage him/her. it can also be really helpful if you reward him/her somehow after they use the bathroom. Never scold them or punish them for having accidents. It does take time though (all depending on the child) to understand and get the routine down.
Hope this helps

m&m'S are a good potty training tool.

Is your child hiding or avoiding the toilet when he goes? is constipation an issue? or holding it in to long? stay consistant - put a jar of life savers or gummies in the bathroom after he makes a poooh in the potty reward every time. Consistancy after meals just before bed put him on the potty- have Dad show if it is a boy how he goes.. get some potty books at the library and put a Lava Lamp in the bathroom for him to look at if it takes him a extended period of time. this helps relax the muscles-