Prepositional Phrases

Prepositional phrases are often optional modifiers in the sentence rather than the central elements. Nonetheless, prepositional phrases appear over and over, and so it's worth examining how these phrases work in some detail.

We have already defined prepositions as a class of words that most commonly express relationships of space or time, or which mark syntactic functions.

Examples of Prepositions:

Spatial Relationship: behind the house
Temporal Relationship: after the party
Syntactic Function: the crux of the matter

Like other major word classes, prepositions are the heads of their own phrases. Prepositions are typically followed by a complement, called the object of the preposition. Most of the time, the object of the preposition is a noun phrase. In other words, the abstract phrase structure generally looks like this:

As we will see shortly, there are exceptions to this rule, but this pattern is so typical that it is worth memorizing. If you see a word that you think is a preposition, look for the noun phrase after it.



Prepositional phrases have a variety of functions. They can modify a noun, as in "the child with a runny nose," or verbs, as in "she came from Panama." When PPs modify verbs, they have functions that can often be filled by adverb phrases, or occasionally by other phrase types as well. Constituents that function in this role are sometimes called adverbials, because these constituents answer adverb-like questions such as when, where, how, or why. Similarly, PPs that modify nouns are sometimes called adjectivals. But be careful with these terms. They do not imply that the PPs actually become adverbs or adjectives. Remember that adjective and adverb are categories for words, not for phrases. The terms adverbial and adjectival simply tell you what sort of constituent the phrase modifies. Because this information can also be conveyed by a tree diagram, we won't use these particular terms much, but you should be aware of them, since other works on English grammar use them frequently. We will have more to say about the various roles that PPs fill after we have finished our survey of phrase types.

Infinitive 'to'

Not everything that looks like a preposition actually behaves like one. For example, the word to followed by a verb phrase forms an infinitive phrase. These infinitive phrases, which we will examine more closely in a later chapter, are verb phrases, not prepositional phrases. We can see this if we contrast infinitive to with the preposition. (1a) My kids always want [to go] [to Disneyland]. In this sentence, the verb want has two constituents that begin with to, but the first is followed by the verb go, and the second by an NP. There are several ways in which the first instance of to behaves very differently from the second. Most prepositions, including to, allow the degree words right or straight. The infinitive marker does not: (1b) My kids always want to go straight to Disneyland. (1c) *My kids always want straight to go to Disneyland. The infinitive marker also permits ellipsis. That is, the verb phrase after the infinitive marker can be omitted if it can be understood from context. The preposition cannot: (1d) My kids always want to. (1e) *My kids always want to go to. Finally, if we say that infinitive to is a preposition, we must conclude that "to go to Disneyland" functions as a PP, but notice that other PPs cannot be substituted for an infinitive phrase: (1f) *My kids always want to Disneyland. (1g) *My kids always want by the car. We will label the infinitive marker INF, but will not analyze the structure of infinitive phrases until later.


Compare the following two sentences:

(2) Ken looked up her number.
(3) Ken looked up her dress.

A little scrutiny will show that up does not have the same function in both sentences. For example, while we can create a cleft sentence with up her dress, we can't do the same thing with up her number:

(2a) *Up her number is what Ken looked.
(3a) Up her dress is where Ken looked.

Also, we can move up to the end of the first sentence, but not the second:

(2b) Ken looked her number up.
(3b) *Ken looked her dress up.

Both these rearrangements demonstrate that up her dress forms a constituent, but up her number does not.

Additionally, we can replace up her dress with other phrases that indicate direction:

(4) Ken looked across the courtyard.
(5) Ken looked under his bed.
(6) Ken looked away from the accident.

But we cannot do the same thing with up in (2) and still have the verb mean the same thing. In other words, the meaning of looked up as a compositional unit differs from that of looked by itself.

Finally, sentence (3) allows right/straight modification, but sentence (2) does not:

(2c) *Ken looked right up her number.
(3c) Ken looked right up her dress.

All of these differences indicate that up in in (3) behaves like a typical preposition, but in sentence (2) it does not. Words that function in this unusual way are called . A particle forms a one-word phrase that can, but doesn't have to, appear between the verb and the direct object. Historically, most particles derive from prepositions, but their behavior is so different from ordinary prepositions that we will classify them separately. Particles usually combine with the verb to produce a specific idiomatic meaning that is different from a verb and a prepositional phrase.

Because up her number in sentence (2), does not constitute a single constituent, we analyze her number as a direct object, which makes look a transitive verb. Thus we will diagram the sentence like this:

particle diag 1

If the particle follows the verb, the diagram looks like this:

particle diag 2

These diagrams imply that we consider particles to be separate constituents within the verb phrase. Some grammar books call verb + particle combinations "multiword verbs." That name implies that the particle is actually part of the verb. We won't use that terminology—the particle isn't actually part of the verb. The fact that it can appear after the direct object demonstrates that. But we still must be able to distinguish verbs with particles from free combinations of verbs and prepositional phrases. Fortunately, the test is relatively straightforward. If the sentence can be transformed so that the word appears after the object, it's a particle:

(7a) The bank turned down the Johnsons
(7b) The bank turned the Johnsons down.

Notice that if the object is an unstressed pronoun, the particle cannot appear between the verb and the direct object. In this case, it must come after the object:

(7c) The bank turned them down
(7d) *The bank turned down them.

If you can create a cleft sentence by moving the word along with the noun phrase, then it's a prepositional phrase:

(8a) I put my socks in the drawer.
(8b) In the drawer is where I put my socks.

This test, though, is not definitive. If you can move the phrase, it is a PP, but some verbs are followed by prepositional phrases that cannot be moved:

(9a) Jane disposed of the remaining objections.
(9b) *It was of the remaining objections that Jane disposed.

We continue to call of the remaining objections a prepositional phrase because of cannot be moved like true particles:

(9c) *Jane disposed the remaining objections of.

Prepositions Without NP Complements

The presence of a noun phrase after a preposition is so common that traditional grammar books often state that a preposition must always be followed by a noun phrase. Certain exceptions, however, make it clear that we cannot accept that assertion.

First, prepositions will sometimes have other prepositional phrases as complements:

(10) The plane emerged from behind the cloud.

From and behind are both prepositions. But notice that from behind the cloud forms a single constituent. You can move it to the front of a cleft sentence:

(10a) From behind the cloud is where the plane emerged.

One way to save this phrase for a traditional definition of prepositions would be to assume that from behind is a complex preposition. In other words, that a two-word sequence has become fossilized and functions as a single unit. But that interpretation won't work. We can move "behind the cloud" independently of from:

(10b) Behind the cloud is where the plane emerged from.

At the same time, we cannot interpret from as a particle, since it does not behave like other particles. In particular, we can't move it to the end of the sentence:

(10c) *The plane emerged behind the cloud from.

The prepositional phrase behind the cloud is actually nested inside a larger PP, headed by from:

diagram from behind the cloud

A certain number of prepositions also occur with an adjective as a complement:

Examples of P + Adj Combinations
at first
at last
for certain
for sure
in brief
in private
of late
of old

Some prepositions can take clauses as complements:

(11) We arrived [after [the party had finished]].

Traditional grammar books classify after in (11) as a subordinating conjunction. But once we realize that prepositions don't need to be followed by noun phrases, there seems to be no reason to make this distinction, and we will not do so.

Sometimes, a word that seems to be a preposition appears alone. Compare these sets of sentences:

(12a) Rivera looked up the stairs.
(12b) Rivera looked up.
(13a) I saw him before the party.
(13b) I saw him before.

Traditional grammar treats the italicized words in (12a) and (13a) as prepositions, but those in (12b) and (13b) as adverbs, once again arguing that the (b) sentences have no noun phrase following up and before, and therefore they must be some other part of speech.

But do up and before really behave like other adverbs? Notice that they can be modified by right/straight, like prepositions and unlike adverbs.

(12c) Rivera looked straight up.
(12d) *Rivera looked straight quickly to his left.
(13c) I saw him right before.
(13d) *I saw him right immediately.

So even though up and before appear in one-word phrases, they continue to behave like prepositions more than like adverbs. To make an analogy with verbs, some prepositions can be intransitive, and do not need any complement at all.