Can he reach over the toilet bowl yet? If not, he will need something to stand on - but not too high. Put a ping pong ball - draw a face on it with permanent marker if you have one - into the toilet bowl and encourage him to try to hit it. The best way is probably just to show him yourself. My sons have always peed standing up - it makes it much easier when you have to take them behind a tree!
I taught my son to pee standing up by holding the potty in the necessary postion for him and getting him to aim at the centre of the potty,then progressed to a step near the toilet and aiming for the very centre of the pool of water in the toilet.
Kids love to be 'grown up' and they love to imitate the adults in their life. One of the best ways to teach kids anything is by demonstration.
So, when Junior 'needs to go', give him a challenge "I bet you can't do it like Daddy" and provide him with a demonstration. He'll soon prove you wrong ;-)
In France all boys learn to pee in the garden or against a tree hidden in the park. This means that later on in life they have no qualms about peeing on the side of the road even when in public. Leave the toilet to the ladies!
coccinelle - looks like I live in France and didn't even know it! my boys love peeing outdoors - I now have to retrain them in the other direction as they are now 8 and 7 (but look older) and it is not so acceptable for them to go for a quick pee in public, unless it is a layby when you don't really have a lot of choice - they cant always wait until the next service area.
i really wouldnt worry about it he will do it in time, weird as it is my hubby is 36 and will only pee standing up at urinals! at home etc he always sits down always has done, i cant understand it and he doesnt have a reason for it.
I can't understand why men have to stand up, unless they are using a urinal, or course. I go sailing and have sailed with men who complain that they have to bend down in the heads because the ceilings are so low. They end up missing the loo when the boat rocks! HeLLO! How about sitting down!