So, how do you usually answer this demand? Were I as quick in Latin as I were in English (although time in Oklahoma threatens to slow my speech patterns), I would try to say something clever. Instead, though, I tend to default to "aliquid Latine", which, when asked, I back-translate as "something in Latin". Then, of course, I am drilled on how to say "shut up" and other such phrases. I'm sure you know the routine.