This word is commonly used as a preposition because it can help state the location or the date. For example, in the sentence below:
The gun is lying on the table.
The word “on” is categorized as a preposition because it expresses where the “gun” is located.
a. physically in contact with and supported by (a surface)
- The freshly baked cookies are on the counter.
b. indicating the day or part of a day during which an event takes place
- The crime was reported on June 24.
c. having (the thing mentioned) as a topic
- I found an interesting book on mental disorders.
d. used as a function word to indicate a source of attachment or support
- It is much better if you would just attach it on a string.
The word “on” can also serve as an adverb on various instances, when it modifies a verb. Take for example, the sentence below:
He put his new shoes on.
In this sentence, the word “on” modifies the verb “put,” and is therefore considered as an adverb.
a. in or into a position of continuance
- I ordered him to switch the lights on.
Pressure will build up inside when the cover is on tight.
The word “on” functions as an adjective because it modifies the noun “cover.”
a. attached to or covering something
- Water loss is slower when the lid is on.
b. being in operation
- I studied while the radio is on.
c. taking place or being broadcast
- The game is on.
d. performing or speaking in public
- The band will be on in 30 minutes.