Why Do We Use Prepositions?

A preposition is a word or group of words used before a noun, pronoun, or noun phrase to show direction, time, place, location, spatial relationships, or to introduce an object.

Why do we need prepositions?

Prepositions hold a privileged position as parts of speech in that they are a 'closed class'. ... While prepositions are limited in number, they are important because they act as vital markers to the structure of a sentence; they mark special relationships between persons, objects, and locations.

What is the main purpose of using preposition?

Prepositions (e.g., on, in, at, and by) usually appear as part of a prepositional phrase. Their main function is to allow the noun or pronoun in the phrase to modify another word in the sentence.