A verb is a word (part of speech) that usually denotes an action (bring, read), an occurrence (decompose, glitter), or a state of being (exist, stand). Depending on the language, a verb may vary in form according to many factors, possibly including its tense, aspect, mood and voice. It may also agree with the person, gender, and/or number of some of its arguments (subject, object, etc.).
The number of arguments that a verb takes is called its valency or valence. Verbs can be classified according to their valency:
The number of arguments that a verb takes is called its valency or valence. Verbs can be classified according to their valency:
- Intransitive (valency = 1): the verb only has a subject. For example: "he runs", "it falls".
- Transitive (valency = 2): the verb has a subject and a direct object. For example: "she eats fish", "Mike hunts deer".
- Ditransitive (valency = 3): the verb has a subject, a direct object and an indirect or secondary object. For example: "I gave her a book," "She sent me flowers."
It is impossible to have verbs with zero valency. Weather verbs are often impersonal (subjectless) in null-subject languages, like Spanish, where the verb llueve means "It rains". In English, they require a dummy pronoun, and therefore formally have a valency of 1.
The intransitive and transitive are typical, but the impersonal and objective are somewhat different from the norm. In the objective the verb takes an object but no subject, the nonreferent subject in some uses may be marked in the verb by an incorporated dummy pronoun similar to the English weather verb (see below). Impersonal verbs take neither subject nor object, as with other null subject languages, but again the verb may show incorporated dummy pronouns despite the lack of subject and object phrases. Tlingit lacks a ditransitive, so the indirect object is described by a separate, extraposed clause.
English verbs are often flexible with regard to valency. A transitive verb can often drop its object and become intransitive; or an intransitive verb can take an object and become transitive. Compare:
The intransitive and transitive are typical, but the impersonal and objective are somewhat different from the norm. In the objective the verb takes an object but no subject, the nonreferent subject in some uses may be marked in the verb by an incorporated dummy pronoun similar to the English weather verb (see below). Impersonal verbs take neither subject nor object, as with other null subject languages, but again the verb may show incorporated dummy pronouns despite the lack of subject and object phrases. Tlingit lacks a ditransitive, so the indirect object is described by a separate, extraposed clause.
English verbs are often flexible with regard to valency. A transitive verb can often drop its object and become intransitive; or an intransitive verb can take an object and become transitive. Compare:
- I moved. (intransitive)
- I moved the book. (transitive)
In the first example, the verb move has no grammatical object. (In this case, there may be an object understood - the subject (I/myself). The verb is then possibly reflexive, rather than intransitive); in the second the subject and object are distinct. The verb has a different valency, but the form remains exactly the same.
In many languages other than English, such valency changes are not possible like this; the verb must instead be inflected for voice in order to change the valency.
In many languages other than English, such valency changes are not possible like this; the verb must instead be inflected for voice in order to change the valency.
