I had a hard time phrasing the actual question title—hopefully this doesn't mean it's too subjective—, but I'm curious about why positive (or negative) statements can be terminated by negative (or positive) questions:
- You do like apples, don't you?
- We can't all be rich, can we?
Why is it (arguably) common to turn a general statement into a question like this when the intent remains the same? Is this a common use of a rhetorical question? If so, what is afforded by not simply making a statement without turning it into a question?