Answer:
How can a pants pocket be empty and still have something in it?
Brings the sky a lot closer.
Tickle with your fingers and a song it will sing. Be careful, though, you may break a string. What is it?
Never ahead, ever behind, yet flying swiftly pastΝΎ For a child I last forever, for adults I'm gone too fast.
Makes apples fall from trees
People take me on walks and I run and have fun. What am I?