adjective
Definition: This word is used to describe something that is in operation, happening, or planned. It can also refer to being in a position or state of activity.
Example: The television is on and the kids are watching their favorite show.
adverb
Definition: In a state of being attached to or covering something, or in a position of contact with something.
Example: Please put your shoes on before entering the house.
preposition
Definition: This word is used to show a relationship between things, often indicating position, direction, or a topic.
Example: The book is on the table.