Answer:
If you are to keep it, you must first give it to me. What is it?
What pulls you down and never lets go?
The day is their night and the night is their day, when I shout and they shout back I run away.
They are two brothers. However much they run, they do not reach each other.
What is found over your head but under your hat?
People take me on walks and I run and have fun. What am I?