Answer:
I belong to you but others use me more often than you do. What am I?
I can go through glass without breaking it.
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
If I drink I die. If I eat I am fine. What am I?
I am heavy forward, but backward I'm not. What am I?
What begins and has no end? What is the ending of all that begins?