• definition of “voice”
The distinction between the passive and the active voice makes it possible to view the action described in an English clause in two different ways: In an active clause, the subject is typically the agent and the object is typically the recipient (or “affected particpant”). In a passive clause, the object of the active clause becomes the subject, and the subject of the active clause is either omitted or becomes the prepositional object of an adverbial by- phrase. There are also changes to the verb element of the clause: an appropriate form of the verb be is added as an auxiliary, followed by the past participle of the main verb. For example:
Harry stole Dick’s sandwich
Dick’s sandwich was stolen by Harry
• the use of the passive
- Generally speaking, the active is much more frequently used than the passive. However, from one context to another, there are striking differences in the frequency of the passive. It is more common in factual than in fictional writing, and in scientific writing and news reporting it is up to ten times as common as it is in less “objective” contexts.
- Cases of the “full” passive in which the verb element is followed by an adverbial by-phrase are much less common than cases in which the adverbial is omitted. In fact, about four times out of five, no by-phrase is present.
The most common reasons for omitting the by-phrase in the passive are: 1. the “agent” — the person or thing that would be referred to by the subject in the active — is unknown; and, 2, the agent is obvious or unimportant. To return to the example used above, it is easy to imagine a situation in which we know that Harry’s sandwich has been stolen, but we do not know who stole it. In that case most speakers would prefer to say Harry’s sandwich has been stolen rather than Someone has stolen Harry’s sandwich. To take another example, if Dick has been working on a contract, it would be natural for him to say to Harry, The contract has been signed, rather than, Mr X has signed the contract, because Harry would know without being told who had signed.
• an ESL note:
Misunderstanding and confusion concerning the passive voice is a primary source of errors made by ESL students, particularly in written work. Most of these errors, result from an inability to understand when the passive is appropriate and when not; a particularly common and fundamental error is attempting to put an intransitive verb such as happen into the passive. (See, for example, the second item in Error Sheet #2.)