A
noun phrase is either a single noun or pronoun or any group of words
containing a noun or a pronoun that function together as a noun or
pronoun, as the subject or object of a verb.
For example, ‘they’, ‘books’, and ‘the books’ are noun phrases, but ‘book’ is just a noun.
Noun
phrases normally consist of a head noun, which is optionally modified
("pre-modified" If the modifier is placed before the noun; "post
modified" if the modifier is placed after the noun). Possible modifiers
include:
* Determiners: articles (the, a), demonstratives (this, that), numerals (two, five, etc.), possessives (my, their, etc.), and quantifiers (some, many, etc.). In English, determiners are usually placed before the noun;
* Adjectives (the red ball); or
* Complements, in the form of a prepositional phrase (such as: the student of physics), or a That-clause (the claim that the earth is round);
* Modifiers; pre-modifiers if placed before the noun and usually either as nouns (the university student) or adjectives (the beautiful lady), or post-modifiers if placed after the noun. A post modifier may be either a prepositional phrase (the man with long hair) or a relative clause (the house where i live).
The difference between modifiers and complements is that complements
complete the meaning of the noun; complements are necessary, whereas
modifiers are optional because they just give additional information
about the noun.
Noun
phrases can make use of an apposition structure. This means that the
elements in the noun phrase are not in a head-modifier relationship, but
in a relation of equality. An example of this is I, Caesar, declare ..., where "Caesar" and "I" do not modify each other.
The head of a noun phrase can be implied, as in "The Bold and the Beautiful" or Robin Hood's "rob from the rich and give to the poor";
an implied noun phrase is most commonly used as a generic plural
referring to human beings. Another example of noun phrase with implied
head is I choose the cheaper of the two.
That noun phrases can be headed by elements other than nouns—for instance, pronouns (They came) or determiners (I'll take these)—has
given rise to the postulation of a determiner phrase instead of a noun
phrase. The English language is not as permissive as some other
languages, with regard to possible heads of noun phrases. German, for
instance, allows adjectives as heads of noun phrases, as in Gib mir die Alten for Give me the olds (i.e. old ones).
