Editing Phrase structure grammar (section)

{{Linguistics|Grammar}}{{Short description|Type of grammar based on constituent entities}}

The term '''phrase structure grammar''' was originally introduced by [[Noam Chomsky]] as the term for [[grammar]] studied previously by [[Emil Post]] and [[Axel Thue]] ([[Post canonical system]]s). Some authors, however, reserve the term for more restricted grammars in the [[Chomsky hierarchy]]: [[context-sensitive grammar]]s or [[context-free grammar]]s. In a broader sense, phrase structure grammars are also known as ''constituency grammars''. The defining character of phrase structure grammars is thus their adherence to the constituency relation, as opposed to the dependency relation of [[dependency grammar]]s.