Asking a Negative Question

Asking a negative question is not conducive unless there's a visual component to judge by. For example, "Is anyone not here for Shabbat?" is only going to be answered by those who are not here for Shabbat. Anybody who is in fact here for Shabbat assumes the question isn't directed towards her and remains silent.

HOWEVER, let's say that you were talking to all of us in a room and said "Please raise your hand if you're not here for Shababt." In this example, by asking the (possibly more answerable negative), you get a clear demonstration and answer to your question with seconds.

A good tip to know.