An object of a preposition is a noun or a pronoun that comes after a preposition such as in, at, of, to, by, behind and on to form a prepositional phrase.
The trip (to the island) (on saturday) will last (for three hours).
This sentence contains three objects of prepositions. Islands is the object of the preposition to; Saturday is the object of the preposition on; hours is the object of preposition for.
An object of a preposition can cause confusion in the Structure section of the TOEFL test because it can be mistaken for the subject of a sentence.
To Mike ___ was a big surprise. (A). really (B). the party (C). funny (D). when.
In this example, you should look first for the subject and the verb. You should notice the verb ‘was’ and should also notice that there is no subject. Do not think that Mike is the object of the preposition ‘to,’ and one nounc cannot be both a subject and an object at the same time. Because a subject is needed in this sentence, answer (B), ‘the party,’ is the best answer. Answers (A), (C), and (D) are not correct because they cannot be subjects.
The following chart outlines the key information that you should remember about objects of prepositions:
A preposition is followed by a noun or pronoun that is called an object of the prepositions, if a word is an object of a preposition, it is not the subject.