Noun Phrases (Jurafsky Martin)
As explained in Jurafsky Martin Chapter 12: Constituency Grammars
Three of the most common types of noun phrases that occur in English are pronouns, proper nouns and the construction \(NP \rightarrow \; Det \; Nominal\). This last type is the one that shows syntactic complexity.
They have a head, the central noune in the noun phrase, and various modifiers that can occur before or after the head noun.
The Determiner
Simple lexical determiners include a, the, this, those, any, some.
Determiners can also be more complex expressions, produced by the rule \(Det \rightarrow \; NP \; ‘s\)
Note this is recursive, so we can chain together eg proper nouns in determiners to form complex examples with a sequence of possessives forming a single determiner like:
- Denver’s mayor’s mother’s canceled flight.
determiners may be omitted if the noun they modify is plural. mass nouns also don’t require determination, they don’t tend to pluralize and don’t take the indefinite article. Many abstract nouns are mass nouns (music, homework). Other examples include water, snow, breakfast.
The Nominal
The nominal follows the determiner and contains any pre- or post- head noun modifiers. The simplest form is just a single noun: \(Nominal \rightarrow \; noun\). This is the base case for more complex recursive productions.
predeterminers
Word classes that modify and appear before NPs are called predeterminers, many have to do with number or amount, eg all: “all the flights”.
postdeterminers
Postdeterminers occur after the determiner but before the head noun, these include:
cardinal numbers: “two friends”
ordinal numbers: “the first bus”, “the next day”, “the other flight”
quantifiers: “many flights”, “(a) few days”, “several delays”
adjectives: “a non-stop flight”
adjective phrase (\(AP\)): These can have an adverb before the adjective: “the least expensive flight”
postmodifiers
postmodifiers follow the head noun. Three kinds are common:
prepositional phrases: “all flights from Cleveland”
non-finite clauses: “any flights arriving after eleven a.m.”
relative clauses: “a flight that serves breakfast”
They can be combined.
Prepositional Phrases
Note that prepositional phrases can be chained, eg “a reserveration [on flight 606] [from Tampa] [to Newark]". As such the production rule is recursive:
\[Nominal \rightarrow \; Nominal \; PP\]
Non-finite Clauses
There different kinds of non-finite postmodifiers. The three most common are gerundive (ie -ing); -ed; and infinitive forms.
Gerundive postmodifiers are so-called as they consist of a VP with the gerundive form of the verb, for example:
“any of those [leaving on Thursday]”
“flights [arriving within thirty minutes of each other]”
We can define the following productions for gerundive modifiers:
\[Nominal \rightarrow \; Nominal \; GerundVP\]
\[GerundVP \rightarrow \; GerundV \; NP\]
\[GerundVP \rightarrow \; GerundV \; PP\]
\[GerundVP \rightarrow \; GerundV\]
\[GerundVP \rightarrow \; GerundV \; NP \; PP\]
$$GerundV → \; being \; | \;arriving \; | \; leaving \; | \; … $
For the other types of non-finite postmodifiers, an example of an -ed form is “I need to have dinner served”, “which is the aircraft used by this flight”. An example of an infinitive is “the last flight to arrive in Boston”.
Relative Clauses
A postnominal relative clause, or restrictive relative clause is a clause that often begins with a relative pronoun (that, who), which is then the subject or object of an embedded verb. The production rules for a subject would look like:
\[Nominal \rightarrow \; Nominal \; RelClause\]
\[RelClause \rightarrow \; (who \; | \; that) \; VP\]
Examples include:
A flight that serves breakfast
A flight that leaves at ten tomorrow
A flight that Billy’s mother can get