Hey, cool, a question I can answer. I don't stutter, but I have friends who do. I guess this is a typical reaction of someone who doesn't stutter the first time they meet someone who stutters severely: 1) Confusion (What's going on? What's happening here?) 2) Realisation (Oh, this person apparently has difficulty speaking.) 3) Uncertainty (How should I behave? What's the appropriate reaction? Should I make eye contact? Should I finish this person's sentences when I can?) 4) Curiosity (How does this work? Why can't this person speak normally? Will they mind if I ask about it?) If they're a mature person, they'll realise that it could be a sensitive topic and they won't ask. If they're a particularly immature or insecure person, they'll have a hard time dealing with their uncertainty and maybe they'll deal with it by mocking you. Needless to say, this reflects badly on them, not you. I'd guess it's rare to get this reaction unless you're dealing with children? I should probably also say that, as someone who doesn't stutter, stuttering doesn't seem to be that big a deal. At its mildest, it's barely noticeable. We all have moments of disfluency, it's nothing remarkable. Most of us don't think of ourselves as unusual, so when we momentarily stumble over our words or we talk to someone else who does this, we mentally skate right over it and don't really notice. You'd have to stutter fairly severely before anyone would really raise an eyebrow. Even when stuttering is quite severe, it still doesn't instinctively strike me as a big deal after the initial surprise has worn off. It can slow the conversation down a bit, sure, but so can interference on a phone line. It's just a mildly inconvenient natural phenomenon that's happening. It isn't anyone's fault, and you still want to know exactly what the person has to say.