‘On’ is a preposition. Prepositions are words used to link nouns, pronouns, or phrases to other words in a sentence. They typically indicate relationships in terms of time, place, direction, or manner.
In the case of ‘on,’ it can describe a location, as in ‘The book is on the table,’ indicating that the book is resting atop the table. It can also denote a specific day or date, such as ‘I’ll see you on Monday.’ Therefore, understanding how ‘on’ functions in sentences helps clarify the relationship between different elements.