Simple Definition:

A preposition is a word that tells you where or when something is in relation to something else (a word that shows the relationship between a noun or pronoun and other words in a sentence).

For example, in the sentence “The book is on the table,” the word “on” is a preposition because it shows where the book is in relation to the table. In the sentence “She arrived after the party,” the word “after” is a preposition because it shows when she arrived in relation to the party.

Other common prepositions include “in,” “at,” “with,” “to,” and “from.” They can be used to describe location, time, direction, possession, and more.

Very Simple Definition:

A preposition is a word that shows where something is or when something happens in relation to something else. It helps us understand the position or timing of things in a sentence.