Answer:
Take one royal word in the plural and make it singular by adding one letter
A red house is made out of red bricks. A blue house is made out of blue bricks. What is a green house made out of?
What goes up and down the stairs without moving?
What has black spots and a white face, is fat not thin, and helps you to win, but tumbles all over the place?
No sooner spoken than broken. What is it?
Before Google, we actually had to physically look things up in this building full of knowledge.