Hi! Thanks for asking. The best thing you can do is ask them, in private, how they'd like to handle it. There may be specific things that trigger their stutter that you could work around or potential accommodations you could offer them. Also, if they dont have any formal accommodations, it may not be a bad idea to ask if they'd like help getting those. In general, letting someone finish their thought, and not trying to finish their sentences for them is the best thing. Just be patient with them. In the end, the fact that you're putting as much thought and consideration into this is amazing. They will notice it and be grateful. None of my teachers ever asked me how they could help and I really wish they did. I'm 40 now, graduated college, and have a good career but life would have been so much more comfortable for me if anyone just would have asked in a non-judgmental/helpful manner. Good on you and thank you for stepping up.