You're making great offers, and doing exactly what caring teachers do, it's so awesome to see. The compassion is important, and so is encouragement. Encouraging him to power through it is great as well. And his body seizing like that is a secondary symptom of stuttering. When you get caught in a speech block, your body tries its best to force the sounds out and it can cause twitching or seizing like that. I actually just took a public speaking course last year, and it wasn't easy! And my professor never talked to me about my stutter. It sounds like there couldn't be a better situation for him to speak in, considering how you've described it. It is also important to let him navigate his way through the course on his own, and to let him come to *you*. Now that you've offered what you did, he knows he can talk to you and get practice time, and anything he needs. My absolute top advice to teachers all the time, is actually with grading. More important than offering compassion, is to take his stutter into consideration when grading his speeches. I had teachers in elementary school who gave me Cs and Ds on speeches because of "disfluency", and it's really heartbreaking. Telling him that you won't take points off for disfluency and that you will grade him fairly is sure to take a TON of weight off his shoulders. I think a lot of stutterers actually stutter more because they're worried of ruining their speech/grade. It doesn't mean immunity to point-loss, but at least the fluency aspect is looked at more carefully.