One student had asked for my help on his computer. As I was en route across the room, another student tried to snag me with a question. I reminded him he needed to wait his turn, as I was already occupied with Jack's request. Heads of several nearby students shot up quickly when I finished my response, mouths agape. I had to replay the scene in my head to learn why there was such interest in this commonplace scene.
So this is how I learned I need to be careful how I address certain students' names followed immediately by verbs. For instance, "Jack asked..."