Phrase Structure Grammar - Constituency Relation

Constituency Relation

In linguistics, phrase structure grammars are all those grammars that are based on the constituency relation, as opposed to the dependency relation associated with dependency grammars; hence phrase structure grammars are also known as constituency grammars. Any of several related theories for the parsing of natural language qualify as constituency grammars, and most of them have been developed from Chomsky's work, including

• Government and Binding Theory,
• Generalized Phrase Structure Grammar,
• Head-Driven Phrase Structure Grammar,
• Lexical Functional Grammar,
• The Minimalist Program, and
• Nanosyntax.

Further grammar frameworks and formalisms also qualify as constituency-based, although they may not think of the themselves as having spawned from Chomsky's work, e.g.

• Arc Pair Grammar and
• Categorial Grammar.

The fundamental trait that these frameworks all share is that they view sentence structure in terms of the constituency relation. The constituency relation derives from the subject-predicate division of Latin and Greek grammars that is based on term logic and reaches back to Aristotle in antiquity. Basic clause structure is understood in terms of a binary division of the clause into subject (noun phrase NP) and predicate (verb phrase VP).

The binary division of the clause results in a one-to-one-or-more correspondence. For each element in a sentence, there are one or more nodes in the tree structure that one assumes for that sentence. A two word sentence such as Luke laughed necessarily implies three (or more) nodes in the syntactic structure: one for the noun Luke (subject NP), one for the verb laughed (predicate VP), and one for the entirety Luke laughed (sentence S). The constituency grammars listed above all view sentence structure in terms of this one-to-one-or-more correspondence.