First off, thank you for your compassion towards your new student who stutters. I also have a severe stutter, though all of my schooling most times I would dread being called on to answer a question, afraid that I would stutter on one word that I wanted to get out. Be patient. For myself, oftentimes I would just call out an answer if I knew it. If I had to wait for the teacher to call on me, those seconds would create instant anxiety and I would stutter. I think it is wonderful that a friend is joining him, but I also sense from your post that you want the friend to have his or her own good experiences at your school and not to just be the stutterer's protector.