Answer:
It cannot be seen, it weighs nothing, but when put into a barrel, it makes it lighter.
What goes through the door without pinching itself? What sits on the stove without burning itself? What sits on the table and is not ashamed?
When the day after tomorrow is yesterday, today will be as far from Wednesday as today was from Wednesday when the day before yesterday was tomorrow. What is the day after this day?
In the night a mountain, in the morning a meadow.
A building where people and stories are on stage
I can only be played on a windy day
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?