Answer:
You're currently trying to solve one
What is it that given one, you'll have either two or none?
I am neither a guest nor a trespasser in this place. I belong that belongs to me. Where is it?
How many months of the year have 28 days?
Break it and it gets better, immediately set and harder to break again.
Two little holes in the side of a hill. Just as you come to the cherry-red mill.