Answer:
What cleans as it gets dirty only to get clean the more you use it?
Lots of them make up a word, And lots of words are in them. It's easy when you think about it. A while ago we stamped and mailed them.
Take one royal word in the plural and make it singular by adding one letter
In what year did Christmas Day and New Year's Day fall in the same year?
You can't keep this until you have given it. What is it?
When is it bad luck to see a black cat?
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?