Passive Voice

In English, as in many other languages, the passive voice is a grammatical voice in which the subject receives the action of a transitive verb, and passive refers more generally to verbs using this construction and the passages in which they are used. In English, a passive verb is periphrastic; that is, it does not have a one-word form, but consists of an auxiliary verb plus the past participle of the transitive verb. The auxiliary verb usually is a form of the verb to be, but other auxiliary verbs, such as get, are sometimes used. The passive voice can be used in any number of tenses.

In the following passage from the Declaration of Independence, the passive verbs are bolded, while the active verb hold and the copulative verb are are italicized:

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.

The active voice is the dominant voice in English, and many commentators, most famously George Orwell in his essay "Politics and the English Language," have urged that the use of the passive voice should be minimized. However, there is general agreement that the passive is useful when the receiver of the action is more important than the doer
Uses of the passive voice

In spite of the widespread criticism, the passive voice does have important uses and is employed by all skilled writers of English. Orwell's "Politics and the English Language" is itself an example; over 20% of its constructions are passive, an unusually high percentage.

In general, the passive voice should be used when the receiver of the action is more important than the doer, or when the doer is unknown, unimportant, or perhaps too obvious to be worth mentioning, as in these examples:
The child was struck by the car.
The store was robbed last night.
Plows should not be kept in the garage.
Kennedy was elected president.

The passive voice can also be used to make other changes to a sentence's emphasis, including emphasizing a modifying adverb or even the performer of the action:
My remarks have been grossly distorted in the press.
The breakthrough was achieved by Burlingame and Evans, two researchers in the university’s genetic engineering lab.

The passive voice is sometimes used to conceal the performer of an action or the identity of a person responsible for a mistake:
We had hoped to report on this problem but the data was inadvertently deleted from our files.[7]

It is this use of the passive voice, to evade responsibility, that has been the subject of greatest criticism.

The passive voice is often used in scientific writing because of the tone of detachment and impersonality that it helps establish. However, some scientific journals prefer their writers to use the active voice.