A preposition links nouns, pronouns and phrases to other words in a sentence. The word or phrase that the preposition introduces is called the object of the preposition. A preposition usually indicates the temporal, spatial or logical relationship of its object to the rest of the sentence as in the following examples.
The book is on the table.
The book is beneath the table.
The book is leaning against the table.
The book is beside the table.
She held the book over the table.
She read the book during class.
In each of the preceding sentences, a preposition locates the noun book in space or in time. A prepositional phrase is made up of the preposition, its object and any associated adjectives or adverbs. A prepositional phrase can function as a noun, an adjective or an adverb.
The most common prepositions are….
The children climbed the mountain without fear.
In this sentence, the preposition "without" introduces the noun "fear." The prepositional phrase "without fear" functions as an adverb describing how the children climbed.
There was rejoicing throughout the land when the government was defeated.
Here, the preposition "throughout" introduces the noun phrase "the land." The prepositional phrase acts as an adverb describing the location of the rejoicing.
The spider crawled slowly along the banister.
The preposition "along" introduces the noun phrase "the banister" and the prepositional phrase "along the banister" acts as an adverb, describing where the spider crawled.
The dog is hiding under the porch because it knows it will be punished for chewing up a new pair of shoes.
Here the preposition "under" introduces the prepositional phrase "under the porch," which acts as an adverb modifying the compound verb "is hiding."
The screenwriter searched for the manuscript he was certain was somewhere in his office.
Similarly in this sentence, the preposition "in" introduces a prepositional phrase "in his office," which acts as an adverb describing the location of the missing papers.