Degree of comparison
In grammar, the voice (also called diathesis) of a verb describes the relationship between the action (or state) that the verb expresses and the participants identified by its arguments (subject, object, etc.). When the subject is the agent or actor of the verb, the verb is in the active voice. When the subject is the patient, target or undergoer of the action, it is said to be in the passive voice.
For example, in the sentence:
the verb "ate" is in the active voice, but in the sentence:
the verbal phrase "was eaten" is passive.
In a transformation from an active-voice clause to an equivalent passive-voice construction, the subject and the direct object switch grammatical roles. The direct object gets promoted to subject, and the subject demoted to an (optional) complement. In the examples above, the mouse serves as the direct object in the active-voice version, but becomes the subject in the passive version. The subject of the active-voice version, the cat, becomes part of a prepositional phrase in the passive version of the sentence, and could be left out entirely.
The English language uses a periphrastic passive voice; that is, it is not a single word form, but rather a construction making use of other word forms. Specifically, it is made up of a form of the auxiliary verb to be and a past participle of the main verb. In other languages, such as Latin, the passive voice is simply marked on the verb by inflection: poemam legit "He reads the poem"; poema legitur "The poem is read".
Some languages (such as Sanskrit, Icelandic and Ancient Greek) have a middle voice. The middle voice is in the middle of the active and the passive voice because the subject cannot be categorized as either agent or patient but has elements of both. An intransitive verb that appears active but expresses a passive action characterizes the English middle voice. For example, in The casserole cooked in the oven, cooked appears syntactically active but semantically passive, putting it in the middle voice. In Classical Greek, the middle voice is often reflexive, denoting that the subject acts on or for itself, such as "The boy washes himself", or "The boy washes". It can be transitive or intransitive. It can occasionally be used in a causative sense, such as "The father causes his son to be set free", or "The father ransoms his son".
Many deponent verbs in Latin represent survivals of the Proto-Indo-European middle voice; many of these in turn survive as obligatory pseudo-reflexive verbs in the Romance languages such as French and Spanish.
Some languages have even more grammatical voices. For example, Classic Mongolian features five voices: active, passive, causative, reciprocal and cooperative.
The antipassive voice deletes or demotes the object of transitive verbs, and promotes the actor to an intransitive subject. This voice is very common among ergative–absolutive languages (which may feature passive voices as well), but rare among nominative–accusative languages.
There are also phenomena that look at first glance like they change the valence of a verb, but in fact do not. So called hierarchical or inversion languages are of this sort. Their agreement system will be sensitive to an external person or animacy hierarchy (or a combination of both): 1 > 2 > 3 or Anim > Inan and so forth. E.g., in Meskwaki (an Algonquian language), verbs inflect for both subject and object, but agreement markers do not have inherent values for these. Rather, a third marker, the direct or inverse marker, indicates the proper interpretation: ne-wa:pam-e:-w-a [1-look.at-DIR-3-3Sg] "I am looking at him", but ne-wa:pam-ekw-w-a [1-look.at-INV-3-3Sg] "He is looking at me". Some scholars (notably Rhodes) have analyzed this as a kind of obligatory passivization dependent on animacy, while others have claimed it is not a voice at all, but rather see inversion as yet another kind of alignment type, parallel to nominative/accusative, ergative/absolutive, split-S, and fluid-S alignments.
Topic-prominent languages like Mandarin tend not to employ the passive voice as frequently. Mandarin-speakers construct the passive voice by using the coverb bèi and rearranging the usual word order. For example, this sentence using active voice:
Note: the first line is in Traditional Chinese while the second is Simplified Chinese.
|"A dog bit this man."|
corresponds to the following sentence using passive voice. Note that the agent phrase is optional.
|"This man was bitten (by a dog)."|
In addition, through the addition of the auxiliary verb "to be" (shì) the passive voice is frequently used to emphasise the identity of the actor. This example places emphasis on the dog, presumably as opposed to some other animal:
|"This man was bitten by a dog."|
Although a topic-prominent language, Japanese employs the passive voice quite frequently, and has two types of passive voice, one that corresponds to that in English and an indirect passive not found in English. This indirect passive is used when something undesirable happens to the speaker.
|"His wallet was stolen by a thief."|
|"I was lied to by her." (or "She lied to me.")|
Some languages do not contrast voices, but have other interesting constructions similar to this. For example, Baltic-Finnic languages such as Finnish and Estonian have a "passive", expressed by conjugating the verb in a never-mentioned "common person" (called "passiivi" or in the older grammar theories "IV persoona" in Finnish). The function is simply leaving out the agent. Also transitivity may be used, such that the fourth-person Ikkuna hajotettiin, which uses the transitive, means "Someone broke the window", while the fourth-person Ikkuna hajosi uses the anticausative, and means "The window broke".
Celtic languages possess a person/number inflection called the "autonomous" or "impersonal", which has been associated with a passive interpretation, though its syntax is different from canonical passives because the patient of the action is in the accusative, not the nominative. It can be translated into English as the nebulous "they", "one", or the impersonal "you". For example, the common sign interdicting tobacco consumption:
The difference between the autonomous and a true passive is that to the speaker, the autonomous indicates that there is in fact no agent, whereas the passive indicates the demotion of an agent. In English, the formation of the passive allows the optional inclusion of an agent in a prepositional phrase, "by the man", etc. Where English would leave out the noun phrase, Irish uses the autonomous, where English includes the noun phrase, Irish uses its periphrastic passive - which can also leave out the noun phrase:
|The tobacco was smoked||(by the man)|
|Bhí||an tabac||caite||(ag an bhfear)|
|Was||the tobacco||consumed||(by the man)|
Some languages draw a distinction between static (or stative) passive voice, and dynamic (or eventive) passive voice. Examples include German, Swedish, Spanish and Italian. "Static" means that an action was done to the subject at a certain point in time resulting in a state in the time focussed upon, whereas "dynamic" means that an action takes place.
Static passive auxiliary verb: sein
Dynamic passive auxiliary verb: werden
Der Rasen ist gemäht ("The lawn is mown", static)
Der Rasen wird gemäht ("The lawn is being mown", literally "The lawn becomes mown", dynamic)
Static passive auxilliary verb: vara (är, var, varit)
Dynamic passive auxilliary verb: bli (blir, blev, blivit) Dynamic passive in Swedish is also frequently expressed with the s-ending.
The vara passive is often synomynous with, and sometimes preferrable to, simply using the corresponding adjective:
Dörren är öppen. "The door is open."
The bli passive is often synomynous with, and sometimes preferrable to, the s-passive:
Dörren öppnas. "The door is (being) opening."
Spanish has two verbs corresponding to English to be: ser and estar. Ser is used to form the ordinary (dynamic) passive voice:
(Note that this construction is very unidiomatic in this case. The usual phrasing would be La puerta se cierra.) Estar is used to form what might be termed a static passive voice (not regarded as a passive voice in traditional Spanish grammar):
In both cases, the verb's participle is used as the complement (as is sometimes the case in English).
Italian uses two verbs (essere and venire) to translate the static and the dynamic passive:
Dynamic passive auxiliary verb: essere and venire (to be and to come)
Static passive auxiliary verb: essere (to be)
In Venetian (Vèneto) the difference between dynamic (true) passive and stative (adjectival) passive is more clear cut, using èser (to be) only for the static passives and vegner (to become, to come) only for the dynamic passive:
Static forms represents much more a property or general condition, whereas the dynamic form is a real passive action entailing "by someone":
Voices found in various languages include: