Short medium clean riddles

What you cannot hold it but it is yours?

Every time you stand up, you lose this. What is it?

I build up castles. I tear down mountains. I make some men blind, I help others to see. What am I?

What goes through towns up hills but never moves?

My best buddy always makes mistakes. But I would easily get rid of the mistakes. What Am I?

They are twin sisters, same height; they work in the kitchen, arm in arm. Whatever is cooked, they always try it first.

You have to look at me to say what I show you. I offer two different purposes but I am spelled the same and I am pronounced the same.

I have just one, but with eight to spare, I am usually friendly, but I sometimes act like I don't care. What am I?

I build bridges of silver and crowns of gold. Who am I?

You measure my life in hours and I serve you by expiring. I'm quick when I'm thin and slow when I'm fat. The wind is my enemy.