# Phrase structure rules

﻿
Phrase structure rules

Phrase-structure rules are a way to describe a given language's syntax. They are used to break a natural language sentence down into its constituent parts (also known as syntactic categories) namely phrasal categories and lexical categories (aka parts of speech). Phrasal categories include the noun phrase, verb phrase, and prepositional phrase; lexical categories include noun, verb, adjective, adverb, and many others. Phrase structure rules were commonly used in transformational grammar (TGG), although they were not an invention of TGG; rather, early TGG's added to phrase structure rules (the most obvious example being "transformations"; see the page transformational grammar for an overview of the development of TGG.) A grammar which uses phrase structure rules is called a phrase structure grammar - except in computer science, where it is known as just a grammar, usually context-free.

Definition

Phrase structure rules are usually of the form $A o B quad C$, meaning that the constituent $A$ is separated into the two subconstituents $B$ and $C$. Some examples are:

:$S o NP quad VP$:$NP o Det quad N1$:$N1 o \left(AP\right) quad N1 quad \left(PP\right)$

The first rule reads: An S consists of an NP followed by a VP. This means "A sentence consists of a noun phrase followed by a verb phrase". The next one: "A noun phrase consists of a determiner followed by a noun.

Further explanations of the constituents: S, Det, NP, VP, AP, PP

Associated with phrase structure rules is a famous example of a grammatically correct sentence. The sentence was constructed by Noam Chomsky as an illustration that syntactically but not semantically correct sentences are possible.

"Colorless green ideas sleep furiously" can be diagrammed as a phrase tree, as below:

where "S" represents a grammatical sentence. The theory of antisymmetry proposed in the early '90s by Richard Kayne is an attempt to derive phrase structure from a single axiom.

Alternative approaches

A number of theories of grammar dispense with the notion of phrase structure rules and operate with the notion of schema instead. Here phrase structures are not derived from rules that combine words, but from the specification or instantiation of syntactic schemata or configurations, often expressing some kind of semantic content independently of the specific words that appear in them. This approach is essentially equivalent to a system of phrase structure rules combined with a noncompositional semantic theory, since grammatical formalisms based on rewriting rules are generally equivalent in power to those based on substitution into schemata.

So, in this type of approach, instead of being derived from the application of a number of phrase structure rules, the sentence "colorless green ideas sleep furiously" would be generated by filling the words into the slots of a schema having the following structure:

And which would express the following conceptual content

X DOES Y IN THE MANNER OF Z

Though they are noncompositional, such models are monotonic. This approach is highly developed within Construction grammar, and has had some influence in Head-Driven Phrase Structure Grammar and Lexical functional grammar.

ee also

* Phrase
* Clause
* Sentence (linguistics)
* Context free grammar
* Phrase structure grammar
* Bare Phrase Structure
* antisymmetry

Wikimedia Foundation. 2010.

### Look at other dictionaries:

• Phrase structure grammar — has several different common meanings.In mathematics, in the area of formal language theory, it is often used as a synonym for context sensitive grammar, which uses phrase structure rules or rewrite rules. However, it is not a precise term, and… …   Wikipedia

• phrase-structure rule — Ling. a rule that generates a sentence or other syntactic construction from words and phrases and identifies its constituent structure. Cf. rewrite rule. * * * phrase structure rule, Linguistics. one of the rules governing the construction of the …   Useful english dictionary

• phrase-structure grammar — /frayz struk cheuhr/, Ling. a grammar that consists of phrase structure rules. [1965 70] * * * …   Universalium

• phrase-structure grammar — /frayz struk cheuhr/, Ling. a grammar that consists of phrase structure rules. [1965 70] …   Useful english dictionary

• Head-driven phrase structure grammar — (HPSG) is a highly lexicalized, non derivational generative grammar theory developed by Carl Pollard and Ivan Sag (1985). It is the immediate successor to generalized phrase structure grammar. HPSG draws from other fields such as computer science …   Wikipedia

• Discontinuous-constituent phrase structure grammar — (DCPSG) (distinct from Discontinuous Phrase Structure Grammar/DPSG) is a formalism for describing discontinuous phrase structures in natural language, such as verb phrases in VSO languages. The formalism was introduced in the slightly more… …   Wikipedia

• Generalised phrase structure grammar — (GPSG) is a framework for describing the syntax and semantics of natural languages. GPSG was initially developed in the late 1970s by Gerald Gazdar. Other contributors include Ewan Klein, Ivan Sag, and Geoffrey Pullum. Their book Generalized… …   Wikipedia

• Head-driven Phrase Structure Grammar — Die Head driven Phrase Structure Grammar (HPSG) ist eine Grammatiktheorie, die in den 1980er Jahren auf der Basis der Wiederbelebung der kontextfreien Phrasenstrukturgrammatiken als Generative Grammatiktheorie aus der Familie der… …   Deutsch Wikipedia

• phrase-struc|ture grammar — «FRAYZ STRUHK chuhr», Linguistics. a grammar consisting of phrase structure rules: »Considerable progress has been made…in using computers to manipulate languages, both vernaculars and programming languages. Grammars called phrase structure… …   Useful english dictionary

• Structure editor — A structure editor, also structured editor, is any document editor that is cognizant of the document’s underlying structure. Structure editors can be used to edit hierarchical or marked up text, computer programs, diagrams, chemical formulas, and …   Wikipedia