I didn't think they worried too much about stuttering until a child was about 6 years these days, because speech developement is different for each child.

The very fact that he is seeing a speech therapist could be making him feel as though he isn't good enough.  It might be time to stop the speech therapy and just let him have a go learning to speak properly on his own.

My now 5 year old had a stutter from the time she could talk until she started school this year.  By being around other children, she very quickly learnt how to speak more properly, and only seems to have a slight stutter when she is trying really hard to get a point across.

Take the pressure off him, and don't try and correct the way he speaks all the time, or he will feel as though is is a 'failure', which he most certainly isn't.  Learning to talk is hard work, and then when they do, finding the off switch is even harder!

my brother had a stuttering problem when he was a child. have you tried reading poems? or stuff that rhymes? like the cat in the hat. and have him read slowly until he gets it. the flow of his tongue reading catchy similar words seems to help.

anyways i hope that helps! good luck.

I dont have any experiance on this but, have you tryed sign language? even just basic or baby sign language so he can at least get across what he want to tell you.

I watched something on the home and health channel about people with stutters, i cant remember exactly what they did but i think they tryed to find what exactly was triggering it (like being nervouse) and they also learnt to talk slower so they had more time to think about what they were trying to say.

Hope this helps a little :)