I know that we all have different extremes in terms of how big or small our stutters are. The one thing I started to realize when I got older about my stutter, is to find out what words, or start of the words trigger it. Forcing it, as I'm sure most if us can agree, makes the stutter worse. So what I do is find a word I know I don't have trouble saying, and say that before the word that is a trigger. As an example I would use the word "the" in front of a trigger word so that the transition is a bit smoother. I know it can sound stupid, but you kind of learn to make it work. But I know that it's embarrassing sometimes when there is a pause due to your stutter. But once you're able to own it and make jokes it doesn't feel as bad. I hope your son is able to take all of the great advice that everyone is giving; and I hope that he is able to get past it and make the most of his life!!