Q: I have a question about these two question sentences: 1. “Will you close the door?” 2. “Won’t you close the door?” Both elicit the same response (“Yes”) while they (seem to) have opposite meanings. How did these “opposite” sentences get identical meanings?
A: Sometimes a question that’s cast in the negative in fact implies a positive, as in “Isn’t she pretty?” … “Won’t you join us?” … “Aren’t they the clever ones?” … “Aren’t you ashamed of yourself?” … “Didn’t I tell you this would happen?”
It’s a long-established form of expression in English. In this case, a negative interrogative sentence only poses as a question. In fact, the speaker is biased in favor of a “yes” answer, so it’s more of a suggestion than a real question.
We wrote a blog item a while back that touches on this phenomenon.
Some kinds of “Why not?” questions act the same way, as in “Why not go to the movies this afternoon?” or “Why not tell the truth?”
But not all negative interrogative sentences are biased in favor of a “yes” answer. Some of them imply that the answer is “no.”
Examples would be “Can’t you do anything right?” and “Didn’t you save your allowance?”
As the Cambridge Grammar of the English Language says, “Questions with negative interrogative form are always strongly biased.”
The bias “can be towards either the negative or the positive answer.”