What Are Prepositions? A preposition is a word that usually tells where or when something is in relation to something else. Examples of Prepositions that Tell Us Where Here are some examples of prepositions that tell us where something is in relation to something else (prepositions highlighted): the boy behind the bush (Here, the preposition "behind" tells us where "the boy" is in relation to "the bush.") a mouse under the stairs (In this example, the preposition "under" tells us where "a mouse" is in relation to "the stairs.") Examples of Prepositions that Tell Us When Here are some examples of prepositions that tell us when something is in relation to something else (prepositions highlighted): the calm before the storm (Here, the preposition "before" tells us when "the calm" is in relation to "the storm.") one second after the bang (In this example, the preposition "after...