Answer:
Never ahead, ever behind, yet flying swiftly past; for a child, I last forever; for an adult, I'm gone too fast. What am I?
He has married many women, but has never been married. Who is he?
I am free the first time and second time but the third time is going to cost you money.
I am the book one can never finish reading
If you drop me I'm sure to crack but give me a smile and I'll always smile back. What am I?
No matter how little or how much you use me, you change me every month.