Answer:
What gets broken when you don't hold it?
Once you know it exists, it no longer exists. What is it?
The part of the bird, that is not in the sky, Which can swim in the ocean and always stay dry. What is it?
You do this into someone's ear when you want to be discreet.
Sometimes you feel it weigh a ton. Yet it is nothing, but somehow still there. Makes you uncomfortable around anyone, But speak its name and it's gone.
This food is a tortilla filled with cheese and sometimes chicken before being heated or cooked.