Answer:
I'm not a bird but I can fly through the sky. I'm not a river but I'm full of water.
I am a person who pretends to be someone else
If a man carried my burden, he would break his back. I am not big but leave silver in my tracks. What am I?
The more you have me, the less you see. Shine a light on me and I flee. What am I?
I sleep by day, I fly by night. I have no feathers to aid my flight. What am I?
What is lighter than what it is made of?