Answer:
Take one royal word in the plural and make it singular by adding one letter
This sparkling globe can float on water. It is light as a feather, but ten giants can't pick it up.
What stays in one corner but travels around the world?
What comes in many varieties and can't be seen or touched, but it often makes you move?
A tasty reward given to well behaved dogs and kids
I spend most of my day eating white. When I am quick enough I get rewarded with fruit and something blue. In a dark room with blue walls I run from the ghosts that roam the halls