A prepositional phrase is a group of words consisting of a preposition, its object, and any words that modify the object. Most of the time, a prepositional phrase modifies a verb or a noun. These two kinds of prepositional phrases are called adverbial phrases and adjectival phrases, respectively.
To these two basic elements, modifiers can be freely added.
Some of the most common prepositions that begin prepositional phrases are to, of, about, at, before, after, by, behind, during, for, from, in, over, under, and with.
Prepositional phrases that modify nouns
When a prepositional phrase acts upon a noun, we say it is behaving adjectivally because adjectives modify nouns. A prepositional phrase that behaves adjectivally is called, quite logically, an adjectival phrase.
In the first of these sentences, in the middle answers the question of which cat the writer thinks is the cutest. Similarly, on Main Street gives us information about which store the writer is describing, and by the lake tells us what kind of cabin the writer’s mother is dreaming about. All of these adjectival phrases provide specificity to a noun in order to enhance our understanding.
Prepositional phrases that modify verbs
When a prepositional phrase acts upon a verb, we say it is behaving adverbially because adverbs modify verbs. A prepositional phrase that behaves adverbially is called an adverbial phrase.
In the first sentence, behind you answers the question “Look where?” In the second, with fervor answers the question “Drank how?”
Prepositional phrases acting as nouns
Less frequently, prepositional phrases can function like nouns in a sentence.
How to avoid excessive prepositional phrases
It is tempting to overuse prepositions and prepositional phrases. If you see more than one preposition for every ten or fifteen words in your writing, you should edit some of them out. You may be surprised at how much more elegant and economical your writing is when you make the effort to do this.
There is nothing grammatically incorrect about the above sentence, but it has two with phrases, an of phrase, and an in phrase, which is a sure sign that it could be written more efficiently.
Here, it was possible to replace one of the prepositional phrases, with caution, with the correlating adverb cautiously. Of Magneto was simply a possessive that could be easily converted to Magneto’s. Four prepositional phrases have been reduced to two.
Another way to reduce prepositional phrases is to switch from a passive voice to an active voice. There is a famous example to illustrate this concept.
Clearly, the passive voice makes this sentence fussy, and the prepositional phrase by the chicken seems a bit silly. It would be better written in an active voice, with the chicken in the driver’s seat, where it belongs.