A noun or pronoun that functions as the object of the preposition and any modifiers it may have follow a preposition. A preposition is one of the eight parts of speech in the English language, and it shows a relationship between its object and other material in the sentence.
The preposition, its object and any modifiers of the object make up the prepositional phrase. A prepositional phrase generally modifies a noun, verb, phrase or clause in a sentence. Location, direction and time are often indicated by a preposition. For example, "above the sofa" is a prepositional phrase in which "above" is the preposition, "sofa" is its object, and "the" is a modifier of the object.