A phrase is a group of words that forms a unit but does not contain a subject and verb. We use many types of phrases in building sentences. This article focuses on prepositional phrases.
A prepositional phrase is a word group that begins with a preposition. A preposition is a joining word that links a noun to another word in a sentence. (For more on prepositions, see prepositions.)
Every prepositional phrase contains at least two words: a preposition at the beginning and at least one noun or nominal (a word or word group acting as a noun). Any modifiers or other words connected to the noun or nominal are also part of the phrase:
at home: (at + noun home)
between Alice and Joe: (between + nouns Alice and Joe)
for you and me: (for + pronouns you and me)
on a dusty dirt road: (on + modifiers a dusty dirt + noun road)
since coming to Canada: (since + nominal coming to Canada)
with what you have: (with + nominal what you have)
A prepositional phrase normally acts as an adjective or an adverb.
As an adjective, the phrase modifies a noun or a nominal and comes immediately after the word it modifies:
We bought the house on the corner.
[on the corner modifies the noun house]
One of the baby birds has fallen out of the nest.
[of the baby birds modifies the pronoun one]
I could hear only the sighing of the wind.
[of the wind modifies the gerund sighing]
As an adverb, the phrase usually modifies a verb. The phrase may be next to the verb or at the beginning or end of the sentence:
The letter sat on the desk all week.
[on the desk modifies the verb sat]
The panther crept silently along the narrow ledge.
[along the narrow ledge modifies the verb crept]
With a puzzled look, Jason followed his sister.
[With a puzzled look modifies the verb followed]
An adverb prepositional phrase may also modify a verbal (i.e., a present or past participle, a gerund or an infinitive):
Racing toward the finish line, Georg left the other runners behind.
[toward the finish line modifies the present participle racing]
The passengers seated at the back couldn’t see.
[at the back modifies the past participle seated]
I don’t mind sailing in rough weather.
[in rough weather modifies the gerund sailing]
Do you want to go to a restaurant for lunch?
[to a restaurant and for lunch modify the infinitive to go]
Some adverb prepositional phrases modify adjectives:
The children were afraid of the barking dog.
[of the barking dog modifies the adjective afraid]
Sometimes an adverb prepositional phrase may follow the linking verb be:
Samina was in the garden.
Occasionally, a prepositional phrase may act as a noun, but this type of structure is unusual in formal writing:
After midnight is the best time to view the comet.
[After midnight acts as the subject of the verb is]