A book. Q: The more you take, the more you leave behind. What are they?

Footsteps. Q: I am not alive, but I grow; I don’t have lungs, but I need air. What am I?

What is it that you can keep after giving it to someone?

A keyboard. Q: What has words but never speaks?

Your word / promise.

Here’s a properly formatted version of an (tricky question/puzzle) with its answer, presented clearly. Q: I have keys but no locks. I have space but no room. What am I?

Fire. Q: What comes once in a minute, twice in a moment, but never in a thousand years?