>and an apology for the last speech This is just me, but I think you should never apologize for stuttering. It's what you have and it's not something you do on purpose. If other people feel inconvenienced by it to the point where they want you to apologize for it, you can tell them to go f*** themselves (not saying your classmates are asking for an apology). Also, don't think of it as a warning. Think of it as addressing the elephant in the room. It's there, might as well address it so that everyone can calm the f*** down.