Definition · Plain-language
Preposition
A preposition is a word that shows the relationship of a noun or pronoun to another word in the sentence — usually of place, time or direction, such as in, on, at, by and with.
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What prepositions show
A preposition expresses a relationship between its object — a following noun or pronoun — and another part of the sentence. Most prepositions cover place, time or direction. Place: the cat sat on the mat, under the chair, beside the door. Time: we met before noon, during the talk, after lunch. Direction: she walked to the station, into the room, towards the exit. Others show more abstract relationships, such as possession (of), accompaniment (with), or purpose (for). Prepositions are a small, closed class of words — English adds new nouns and verbs constantly but rarely new prepositions — yet they appear in almost every sentence.
Prepositions and their objects
A preposition almost always has an object: the noun or pronoun it relates to, which comes after it. Preposition plus object (plus any modifiers) makes a prepositional phrase — "in the morning", "with great care", "to her". Because the object is governed by the preposition, a pronoun object must take its object form: "between you and me", not "between you and I"; "to him", not "to he". The prepositional phrase then works as a single unit in the sentence, acting as an adjective (describing a noun) or an adverb (describing a verb, adjective or clause). Spotting the preposition is the first step to identifying these phrases.
Common questions and the "ending" myth
Two points cause endless debate. First, the old rule that you must never end a sentence with a preposition is a myth with no basis in English grammar; insisting on it can produce stilted sentences, and "What are you looking at?" is perfectly correct. Second, the right preposition is often idiomatic rather than logical — we say "interested in", "good at", "different from" — and these pairings (dependent prepositions) simply have to be learned. Prepositions also combine with verbs to form phrasal verbs (look after, give up), where the combination can take on a meaning quite different from the individual words.
Key facts
At a glance
- Definition: a word linking a noun or pronoun to the rest of the sentence
- Shows: place, time, direction or other relationships
- Examples: in, on, at, by, with, under, before, between, to
- Object: the noun or pronoun that follows (in its object form)
- Forms: a prepositional phrase (preposition + object)
- Myth: ending a sentence with a preposition is not an error
Common misconceptions
What people often get wrong
Often heard: You must never end a sentence with a preposition.
Actually: This is a long-standing myth, not a real rule of English. "What are you waiting for?" is correct and natural; rephrasing to avoid the final preposition often sounds stilted.
Often heard: A pronoun after a preposition keeps its subject form, as in "to he" or "between you and I".
Actually: The object of a preposition takes the object form: "to him", "between you and me". The subject forms (he, I) are only for the doer of an action.
Often heard: There is always a logical reason for which preposition to use.
Actually: Many prepositions are idiomatic and must be learned — we say "interested in", "good at" and "different from" by convention, not by a deducible rule.
Going deeper
