Editing Dependency grammar (section)

==Dependency vs. phrase structure==
Dependency is a one-to-one correspondence: for every element (e.g. word or morph) in the sentence, there is exactly one node in the structure of that sentence that corresponds to that element. The result of this one-to-one correspondence is that dependency grammars are word (or morph) grammars. All that exist are the elements and the dependencies that connect the elements into a structure. This situation should be compared with [[Phrase structure grammar|phrase structure]]. Phrase structure is a one-to-one-or-more correspondence, which means that, for every element in a sentence, there are one or more nodes in the structure that correspond to that element. The result of this difference is that dependency structures are minimal<ref>The minimality of dependency structures is emphasized, for instance, by Ninio (2006), Hudson 2007: 117, and by Osborne et al. (2011).</ref> compared to their phrase structure counterparts, since they tend to contain many fewer nodes.

[[File:Wearetryingtounderstandthedifference (2).jpg|center|Dependency vs. phrase structure]]

These trees illustrate two possible ways to render the dependency and phrase structure relations (see below). This dependency tree is an "ordered" tree, i.e. it reflects actual word order. Many dependency trees abstract away from linear order and focus just on hierarchical order, which means they do not show actual word order. This constituency (= phrase structure) tree follows the conventions of [[Minimalist program|bare phrase structure]] (BPS), whereby the words themselves are employed as the node labels.

The distinction between dependency and phrase structure grammars derives in large part from the initial division of the clause. The phrase structure relation derives from an initial binary division, whereby the clause is split into a subject [[noun phrase]] (NP) and a [[Predicate (grammar)|predicate]] [[verb phrase]] (VP). This division is certainly present in the basic analysis of the clause that we find in the works of, for instance, [[Leonard Bloomfield]] and [[Noam Chomsky]]. Tesnière, however, argued vehemently against this binary division, preferring instead to position the verb as the root of all clause structure. Tesnière's stance was that the subject-predicate division stems from [[term logic]] and has no place in linguistics.<ref>Concerning Tesnière's rejection of the subject-predicate division of the clause, see Tesnière (1959:103–105), and for discussion of empirical considerations that support Tesnière's point, see Matthews (2007:17ff.), Miller (2011:54ff.), and Osborne et al. (2011:323f.).</ref> The importance of this distinction is that if one acknowledges the initial subject-predicate division in syntax as real, then one is likely to go down the path of phrase structure grammar, while if one rejects this division, then one must consider the verb as the root of all structure, and so go down the path of dependency grammar.