“So in short, ask him to become aware of what he is focusing on during a speech block (eg anticipation, stutter pressure, body tension, tensing speech muscles, hearing himself stutter, techniques, word substitution or secondary behaviors).” That could be a really heavy thing to ask a kid who’s probably only 13 or 14 to do. If he’s super motivated to make changes to how he speaks and can do that without feeling like he’s a failure if he stutters, that could be good. But from the research I’ve seen therapy that emphasizes fluency isn’t very effective for people with a lot of avoidances or anxiety about stuttering. But I wonder if he’d be better off with his big brother/sister just giving him a hug and telling him they think he’s awesome as he is, and then doing something he enjoys together (a sport, a game, a hike, whatever) and having fun without his speech being a big deal. Encourage him to talk when he wants to talk and let him know you’re there for him however he needs.