Phrase Structure Grammar - Dependency Relation

Dependency Relation

By the time of Gottlob Frege, a competing understanding of the logic of sentences had arisen. Frege rejected the binary division of the sentence and replaced it with an understanding of sentence logic in terms of predicates and their arguments. On this alternative conception of sentence logic, the binary division of the clause into subject and predicate was not possible. It therefore opened the door to the dependency relation (although the dependency relation had also existed in a less obvious form in traditional grammars long before Frege). The dependency relation was first acknowledged concretely and developed as the basis for a comprehensive theory of syntax and grammar by Lucien Tesnière in his posthumously published work Éléments de syntaxe structurale (Elements of Structural Syntax).

The dependency relation is a one-to-one correspondence: for every element (word or morph) in a sentence, there is just one node in the syntactic structure. The distinction is thus a graph-theoretical distinction. The dependency relation restricts the number of nodes in the syntactic structure of a sentence to the exact number of syntactic units (usually words) that that sentence contains. Thus the two word sentence Luke laughed implies just two syntactic nodes, one for Luke and one for laughed. Some prominent dependency grammars are listed here:

• Algebraic Syntax
• Functional Generative Description
• Lexicase
• Meaning-Text Theory
• Operator Grammar
• Word Grammar

Since these grammars are all based on the dependency relation, they are by definition NOT phrase structure grammars.