Basically, those situations are not the same. Stutter is highly likely to vary across different situations, and that's what you're experiencing. Actually, I've had a stutter happen once in a while, when I was alone. It's got something to do with which mode of performance you're in. You could try something (for fun, I suppose): Record yourself speaking. Play it back to hear it afterwards. Then record yourself speaking, and play it to someone else. Check back with your results, if you will. :) - Also, just to point it out, it's not that there's something _you're_ doing wrong. It's just that stutter works (or should we say, doesn't work) in these various confusing ways. Oh, and do try out speech therapy, if you haven't already. It can help you manage those situations or modes that cause your problems.