Editing Phrase structure rules (section)

{{Short description|Rewrite rule used to describe a given language's syntax}}
'''Phrase structure rules''' are a type of [[rewrite rule]] used to describe a given language's [[syntax]] and are closely associated with the early stages of [[transformational grammar]], proposed by [[Noam Chomsky]] in 1957.<ref>For general discussions of phrase structure rules, see for instance Borsley (1991:34ff.), Brinton (2000:165), Falk (2001:46ff.).</ref> They are used to break down a natural [[language]] sentence into its constituent parts, also known as [[syntactic category|syntactic categories]], including both lexical categories ([[part of speech|parts of speech]]) and [[phrase|phrasal]] categories. A grammar that uses phrase structure rules is a type of [[phrase structure grammar]]<!-- [needs clarification or removal:] - except in [[computer science]], where it is known as just a [[Formal grammar|grammar]], usually [[context-free grammar|context-free]]-->. Phrase structure rules as they are commonly employed operate according to the [[constituent (linguistics)|constituency]] relation, and a grammar that employs phrase structure rules is therefore a [[phrase structure grammar|''constituency grammar'']]; as such, it stands in contrast to [[dependency grammar|''dependency grammars'']], which are based on the [[government (linguistics)|dependency]] relation.<ref>Dependency grammars are associated above all with the work of Lucien Tesnière (1959).</ref>