REPOSITIONS AND PREPOSITIONAL PHRASES
Prepositions are common; they are not flashy. They are sometimes very little words, like on, in, and unlike; sometimes they are two words, like according to. A preposition combined with a noun (or pronoun), in that order, makes a prepositional phrase:
in Duffy's Tavern
on the dashboard of my car
unlike most biologists
according to most moviegoers
Prepositional phrases usually tell where or when. Or, as most instructors are fond of saying, they show relationship, for example, of location (in Duffy's Tavern) or of time (in February).
The formula, with variations
To describe a prepositional phrase we can borrow some math shorthand (although our description does not really function like an equation--the preposition must always come first!):
preposition + noun or pronoun = prepositional phrase
Stuff can be added between, usually in the form of various adjectives, but a prepositional phrase always begins with the preposition and ends with the noun (or pronoun):
preposition + adjectives + noun or pronoun = prepositional phrase
in a yellow submarine
of the best and brightest students
The second example above adds multiple adjectives (as well as a conjunction) but it begins with the preposition and ends with the noun, and that is what matters.
The noun (or pronoun) that ends a prepositional phrase is called the object of the preposition. If all prepositional phrases ended with nouns, you might not care to know this; however, prepositional phrases may also end with pronouns, and those pronouns must be objective pronouns: her (not she), him (not he), me (not I), them (not they), us (not we).
Rossi will come with her and me.
Why council members didn't explain about it was beyond us.
Notice that prepositional phrases may end with double nouns or double pronouns (compound objects of the preposition), as illustrated above.
A complete list of prepositions would be huge. You do not need to know all of them, but become familiar with at least some common prepositions:
The no-subject rule
Is there any practical advantage to knowing about prepositional phrases, you ask? Well, consider that it is a common mistake for beginning writers to misidentify the subject of a sentence (randomly picking out a likely noun, perhaps), make punctuation choices based on this mistake, and end up with basic sentence errors in their writing. And consider further that you will not make this mistake if you remember this rule: a prepositional phrase never contains the subject of a sentence.
This is the advantage to knowing how to recognize prepositions and prepositional phrases in your own writing. You need to be able to identify the subjects of sentences to be sure you have constructed and punctuated them correctly. For example, you must be able to identify subjects in order to avoid creating comma splices and fragments; ESL learners need to be able to identify the subject in order to make sure the verb is in agreement with the subject.
To make this rule work for you, place parentheses around the prepositional phrases in your sentences. Whatever is inside the parentheses is not the subject, no matter how prominently it is placed:
(After the homecoming game), (before midnight), we will leave.
Since the nouns in this sentence, game and midnight, occur in prepositional phrases, they are disqualified as subjects. That leaves only we--a simple pronoun subject buried near the end of the sentence and easily overlooked.
"Preposition" is a function of the word, not the word itself. A preposition, to be a preposition, must be in a prepositional phrase. Sometimes a word on the list of common prepositions above occurs alone in a sentence, without a noun or pronoun following. In the following example, outside is not a preposition at all, but a simple adverb modifying the verb practice:
Please practice your soccer dribbling outside!
For more on adverbs, see the TIP Sheet "Adverbs."
Another preposition look-alike occurs when the word to appears followed by a verb rather than by a noun. This is a type of verbal phrase called an infinitive:
They practiced their dribbling outside to avoid breaking the furniture.
For more on verbals, see the TIP Sheet "Other Phrases: Verbal, Appositive, Absolute."
Yet another preposition look-alike is the phrasal verb-two-word verbs such as check out, run into, or show up:
Carol never showed up for the soccer game on Sunday.
For more information on phrasal verbs, see the TIP Sheet "Two-word (Phrasal) Verbs."
Which prepositions go with which verbs in which expressions is often a matter of custom rather than rule. For ESL students in particular, prepositions can be difficult to master. The prepositions describing when something occurs are a good example. If you wish to state that an event occurred generally within a particular season, week, month, or year, use during or in:
During the winter break I worked at the Heavenly Valley ski resort.
In 2002 the snow was pretty sparse; we're hoping for more this year.
That year we were already getting spring snow conditions in February!
On the other hand, if you are stating that an event occurred on a particular calendar date, weekday, or holiday, use on:
You'd be surprised how many families ski on Christmas.
I'll meet you there on the 24th.
For specific times of day and clock times, use at:
The best time to catch the gondola to the top is at 11:30, just before the lunch rush.
Our favorite ski run of the day is the run from the top at sunset.
In addition, one can be on time for a scheduled event, but in time for an unscheduled one:
He met me at the bottom of the expert run right on time, as we had agreed.
The Ski Patrol arrived just in time to keep Jeff from breaking his neck.
Other expressions mean very different things depending on which prepositions they are paired with, for example, differ from (be dissimilar) and differ with (disagree with). In comparisons, a thing is similar to another thing. We agree with a person, but we agree on a plan and agree to particular actions.