Actually my son has always stuttered but we didn’t think it was a big deal since most kids do grow out of it. But his stutter stayed even as his peers started having more clear speech. It was his 3rd grade teacher who pointed out to get him in speech… not his doctor, not us, not teachers before that particular teacher. For that we are forever grateful to her. I suggest you get an appointment with his doctor and tell them your concern. Idk what school your son is in but ours has a very good speech therapy program so we started there.