Some may assume that the words simple and simpleton are related to each other because of the similarities in their names but actually, they are different from each other. Simpleton is known to be a noun. This means that a person lacks the common sense to do what is right. Simple, on the other hand, is known to be an adjective.
This is used to describe someone who does not want to make any fuss when doing things. Instead of being extravagant, someone may act in a very simple manner. The word simple is normally used as a compliment while when someone is called a simpleton, this might mean that the person is already bordering on being a fool.