Answer:
A harvest sown and reaped on the same day in an unplowed field. Which increases without growing, remains whole though it is eaten within and without. Is useless and yet the staple of nations.
I can be written, I can be spoken, I can be exposed, I can be broken.
What is as big as you are and yet does not weight anything?
I have a tongue, but do not talk. I follow close, but neither run nor walk. Coupled and hitched, but never married. You couldn't bear the load I've carried.
I am mother and father, but never birth or nurse. I'm rarely still, but I never wander.
What did the piece of wood say when he saw the screwdriver and screws approaching?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?