Noun phrase 
A noun phrase , or nominal ( phrase ) , is a phrase that has a noun or pronoun as its head or performs the same grammatical function as a noun . 
Noun phrases are very common cross-linguistically , and they may be the most frequently occurring phrase type . 
Noun phrases often function as verb subjects and objects , as predicative expressions and as the complements of prepositions . 
Noun phrases can be embedded inside each other ; for instance , the noun phrase some of his constituents contains the shorter noun phrase his constituents . 
In some more modern theories of grammar , noun phrases with determiners are analyzed as having the determiner as the head of the phrase , see for instance Chomsky ( 1995 ) and Hudson ( 1990 ) . 
Identification 
Some examples of noun phrases are underlined in the sentences below . 
The head noun appears in bold . 
This election - year 's politics are annoying for many people . 
Almost every sentence contains at least one noun phrase . 
Current economic weakness may be a result of high energy prices . 
Noun phrases can be identified by the possibility of pronoun substitution , as is illustrated in the examples below . 
a . This sentence contains two noun phrases . 
b. 
It contains them . 
a . 
The subject noun phrase that is present in this sentence is long . 
b. 
It is long . 
a . 
Noun phrases can be embedded in other noun phrases . 
b. 
They can be embedded in them . 
A string of words that can be replaced by a single pronoun without rendering the sentence grammatically unacceptable is a noun phrase . 
As to whether the string must contain at least two words , see the following section . 
Status of single words as phrases 
Traditionally , a phrase is understood to contain two or more words . 
The traditional progression in the size of syntactic units is word < phrase < clause , and in this approach a single word ( such as a noun or pronoun ) would not be referred to as a phrase . 
However , many modern schools of syntax - especially those that have been influenced by X - bar theory - make no such restriction . 
Here many single words are judged to be phrases based on a desire for theory - internal consistency . 
A phrase is deemed to be a word or a combination of words that appears in a set syntactic position , for instance in subject position or object position . 
On this understanding of phrases , the nouns and pronouns in bold in the following sentences are noun phrases ( as well as nouns or pronouns ) : 
He saw someone . 
Milk is good . 
They spoke about corruption . 
The words in bold are called phrases since they appear in the syntactic positions where multiple - word phrases ( i.e. traditional phrases ) can appear . 
This practice takes the constellation to be primitive rather than the words themselves . 
The word he , for instance , functions as a pronoun , but within the sentence it also functions as a noun phrase . 
The phrase structure grammars of the Chomskyan tradition ( government and binding theory and the minimalist program ) are primary examples of theories that apply this understanding of phrases . 
Other grammars such as dependency grammars are likely to reject this approach to phrases , since they take the words themselves to be primitive . 
For them , phrases must contain two or more words . 
Components 
A typical noun phrase consists of a noun ( the head of the phrase ) together with zero or more dependents of various types . 
( These dependents , since they modify a noun , are called adnominal . ) 
The chief types of these dependents are : 
* determiners , such as the , this , my , some , Jane 's * attributive adjectives , such as large , beautiful , sweeter * adjective phrases and participial phrases , such as extremely large , hard as nails , made of wood , sitting on the step * noun adjuncts , such as college in the noun phrase a college student * nouns in certain oblique cases , in languages which have them , such as German des Mannes ( " of the man " ; genitive form ) * prepositional phrases , such as in the drawing room , of his aunt * adnominal adverbs and adverbials , such as ( over ) there in the noun phrase the man ( over ) there * relative clauses , such as which we noticed * other clauses serving as complements to the noun , such as that God exists in the noun phrase the belief that God exists * infinitive phrases , such as to sing well and to beat in the noun phrases a desire to sing well and the man to beat 
The allowability , form and position of these elements depend on the syntax of the language in question . 
In English , determiners , adjectives ( and some adjective phrases ) and noun modifiers precede the head noun , whereas the heavier units - phrases and clauses - generally follow it . 
This is part of a strong tendency in English to place heavier constituents to the right , making English more of a head - initial language . 
Head - final languages ( e.g. Japanese and Turkish ) are more likely to place all modifiers before the head noun . 
Other languages , such as French , often place even single - word adjectives after the noun . 
Noun phrases can take different forms than that described above , for example when the head is a pronoun rather than a noun , or when elements are linked with a coordinating conjunction such as and , or , but . 
For more information about the structure of noun phrases in English , see English grammar ¬ß Phrases . 
Syntactic function 
Noun phrases typically bear argument functions . 
That is , the syntactic functions that they fulfill are those of the arguments of the main clause predicate , particularly those of subject , object and predicative expression . 
They also function as arguments in such constructs as participial phrases and prepositional phrases . 
For example : 
For us the news is a concern . 
- the news is the subject argument 
Have you heard the news ? 
- the news is the object argument 
That is the news . 
- the news is the predicative expression following the copula is 
They are talking about the news . 
- the news is the argument in the prepositional phrase about the news 
The man reading the news is very tall . 
- the news is the object argument in the participial phrase reading the news 
Sometimes a noun phrase can also function as an adjunct of the main clause predicate , thus taking on an adverbial function , e.g . 
Most days I read the newspaper . 
She has been studying all night . 
With and without determiners 
In some languages , including English , noun phrases are required to be " completed " with a determiner in many contexts , and thus a distinction is made in syntactic analysis between phrases that have received their required determiner ( such as the big house ) , and those in which the determiner is lacking ( such as big house ) . 
The situation is complicated by the fact that in some contexts a noun phrase may nonetheless be used without a determiner ( as in I like big houses ) ; in this case the phrase may be described as having a " null determiner " . 
( Situations in which this is possible depend on the rules of the language in question ; for English , see English articles . ) 
Noun phrase 
In the original X - bar theory , the two respective types of entity are called noun phrase ( NP ) and N - bar ( N , N ' ) . 
Thus in the sentence 
Here is the big house , both house and big house are N - bars , while the big house is a noun phrase . 
In the sentence I like big houses , both houses and big houses are N - bars , but big houses also functions as a noun phrase ( in this case without an explicit determiner ) . 
In some modern theories of syntax , however , what are called " noun phrases " above are no longer considered to be headed by a noun , but by the determiner ( which may be null ) , and they are thus called determiner phrases ( DP ) instead of noun phrases . 
( In some accounts that take this approach , the constituent lacking the determiner - that called N - bar above - may be referred to as a noun phrase . ) 
This analysis of noun phrases is widely referred to as the DP hypothesis . 
It has been the preferred analysis of noun phrases in the minimalist program from its start ( since the early 1990s ) , though the arguments in its favor tend to be theory - internal . 
By taking the determiner , a function word , to be head over the noun , a structure is established that is analogous to the structure of the finite clause , with a complementizer . 
Apart from the minimalist program , however , the DP hypothesis is rejected by most other modern theories of syntax and grammar , in part because these theories lack the relevant functional categories . 
Dependency grammars , for instance , almost all assume the traditional NP analysis of noun phrases . 
For illustrations of different analyses of noun phrases depending on whether the DP hypothesis is rejected or accepted , see the next section . 
Tree representations 
The representation of noun phrases using parse trees depends on the basic approach to syntactic structure adopted . 
The layered trees of many phrase structure grammars grant noun phrases an intricate structure that acknowledges a hierarchy of functional projections . 
Dependency grammars , in contrast , since the basic architecture of dependency places a major limitation on the amount of structure that the theory can assume , produce simple , relatively flat structures for noun phrases . 
The representation also depends on whether the noun or the determiner is taken to be the head of the phrase ( see the discussion of the DP hypothesis in the previous section ) . 
Below are some possible trees for the two noun phrases the big house and big houses ( as in the sentences Here is the big house and I like big houses ) . 
1. Phrase - structure trees , first using the original X - bar theory , then using the current DP approach : 
2. Dependency trees , first using the traditional NP approach , then using the DP approach : 
The following trees represent a more complex phrase . 
For simplicity , only dependency - based trees are given . 
The first tree is based on the traditional assumption that nouns , rather than determiners , are the heads of phrases . 
The head noun picture has the four dependents the , old , of Fred , and that I found in the drawer . 
The tree shows how the lighter dependents appear as pre-dependents ( preceding their head ) and the heavier ones as post - dependents ( following their head ) . 
The second tree assumes the DP hypothesis , namely that determiners rather than nouns serve as phrase heads . 
The determiner the is now depicted as the head of the entire phrase , thus making the phrase a determiner phrase . 
Note that there is still a noun phrase present ( old picture of Fred that I found in the drawer ) but this phrase is below the determiner . 
History 
An early conception of the noun phrase can be found in First work in English by Alexander Murison . 
In this conception a noun phrase is " the infinitive of the verb " ( p. 146 ) , which may appear " in any position in the sentence where a noun may appear ". 
For example , to be just is more important than to be generous has two underlined infinitives which may be replaced by nouns , as in justice is more important than generosity . 
This same conception can be found in subsequent grammars , such as 1878 's A Tamil Grammar or 1882 's Murby ‚Äôs English grammar and analysis , where the conception of an X phrase is a phrase that can stand in for X . 
By 1912 , the concept of a noun phrase as being based around a noun can be found , for example , " an adverbial noun phrases is a group of words of which the noun is the base word , that tells the time or place of an action , or how long , how far , or how much " . 
By 1924 , the idea of a noun phrase being a noun plus dependents seems to be established . 
For example , " Note order of words in noun- phrase - - noun + adj. + genitive " suggests a more modern conception of noun phrases . 
See also 
* Chunking ( computational linguistics ) * Conservativity * Nominal group ( functional grammar ) 
