Valency (linguistics)

In linguistics, verb valency or valence refers to the number of arguments controlled by a verbal predicate. It is related, though not identical, to verb transitivity, which counts only object arguments of the verbal predicate. Verb valency, on the other hand, includes all arguments, including the subject of the verb.

The linguistic meaning of valence is derived from the definition of valency in chemistry. This metaphor is due to Lucien Tesnière.

Types of valency

There are several types of valency:

*An avalent verb takes no arguments, e.g. "It rains." (Though "it" is technically the subject of the verb, it is only a dummy subject, that is a syntactic placeholder with no true meaning.)
*A monovalent verb takes one argument, e.g. "He sleeps."
*A divalent verb takes two, e.g. "He kicks the ball."
*A trivalent verb takes three, e.g. "He gives her a flower."

The verb requires all of these arguments in a well-formed sentence, although they can sometimes undergo valency reduction or expansion.

For instance, "to eat" is naturally divalent, as in "he is eating an apple", but may be reduced to monovalency in "he is eating". This is called valency reduction.

Verbs that are usually monovalent, like "to sleep", cannot take a direct object. However, there are cases where the valency of such verbs can be expanded, for instance in "He sleeps the sleep of death." This is called valency expansion.

Verb valence can also be described in terms of syntactic versus semantic criteria. The syntactic valence of a verb refers to the number of dependent arguments that the verb can have, while semantic valence describes the thematic relations associated with a verb.

Lexical valency

The term valence has a related technical meaning in lexical semantics that elaborates on the role of argument structure - it refers to the capacity of other lexical units to combine with the given word. For instance, valence is one of the elements defining a construction in some Construction Grammars. This sense of the term, sometimes called Lexical Valency, is related to the above, but is far richer than the numerical notion inherited from chemistry.

ee also

* Verb argument
* Arity
* Verb
* Morphosyntactic alignment
* Transitivity (grammatical category)

External links

* [http://webdoc.gwdg.de/edoc/ia/eese/artic99/herbst/main1.html English Valency Structures - A first sketch]
* [http://www.inst.at/trans/15Nr/04_09/fesenko_alina15.htm The difference between lexical and grammatical valency]
* [http://www.sil.org/linguistics/GlossaryOflinguisticTerms/WhatIsValency.htm What is valency?]