An adpositional phrase is a linguistics term that includes prepositional phrases (usually found in head-first languages such as English) and postpositional phrases (usually found in head-final languages. The difference between the two is simply one of word order.
Both types of adpositional phrases are a syntactic category: a phrase which is treated in certain ways as a unit by a language's rules of syntax. An adpositional phrase is composed of an adposition (in the head position, which is why it lends its name to the phrase) and usually a complement such as a noun phrase. ("Adposition" is simmilarly a generic term for either a preposition or a postposition.) These phrases generally act as complements and adjuncts of noun phrases and verb phrases.
Prepositional Phrase
The bolded phrases are examples of prepositional phrases in English:
- She is on the computer.
- Holly walked down the ramp.
- They walked to their school.
- Dylan ate in the kitchen.
Prepositional phrases have a prepostion as the head of the phrase.
The first example could be diagrammed (using simplified modem notation):
IP
| /
NP VP
| | /
N V PP
| | / /
She is P NP
| / /
on Det N
| |
the computer
Where by convention:
- IP = Inflectional phrase (sentence)
- NP = Noun phrase
- N = Noun
- VP = Verb phrase
- PP = Prepositional phrase
- P = Preposition
- Det = Determiner
The diagram shows that the prepositional phrase in this sentence is composed of two parts: a preposition and a noun phrase. The preposition is in the head position, and the noun phrase is in the complement position. Because English is a head-first language, we usually see the head before the complement (or any adjuncts) when we actually read the sentence. (However, the head comes after the specifier, such as the determiner "the" in the noun phrase above.)
Prepositional phrases generally act as complements and adjuncts of noun phrases and verb phrases.
For example:
- The man from China was enjoying his noodles. (Adjunct of a noun phrase)
- She ran under him. (Adjunct of a verb phrase)
- He gave money to the cause. (Oblique complement of a verb phrase)
- A student of physics. (Complement of a nounn phrase)
- She argued with him. (Complement of a verb phrase)
A prepositional phrase should be confused with the sequence formed by the particle and the direct object of a phrasal verb, as in turn on the light. This sequence is structurally distinct from a prepositional phrase. In this case, "on" and "the light" do not form a unit; the combine independency with the verb "turn".
Another common point of confusion is that the word "to" may appear either as a preposition or as a verbal particle in infinitive verb phrases, such as "to run for president".
Postpositional Phrase
Omitted, not my concern