Answer:
What is it that you must give before you can keep it.
What goes through a door but never goes in. And never comes out?
Runs smoother than any rhyme, loves to fall but cannot climb.
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
A type of hammer that brings a room to order.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?