Answer:
I fly when I'm born. I lie when I'm alive. I run when I'm dead. What am I?
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
I am the kind of a tree that is carried in your hand. What am I?
I break down buildings, I crumble mountains but you can't see me. What am I?
I know a word of letters three. Add two and fewer there will be. What is the word?
I am your mother's brother's only brother in law. Who am I?