Passive Voice

Diferentemente da voz ativa, em que a ênfase está em quem praticou a ação, ou seja, no sujeito, a voz passiva se preocupa em enfatizar o objeto, ou seja, aquele que sofre a ação expressa pelo verbo.
Um exemplo de voz ativa seria:
The men built that house. (Os homens construíram aquela casa).
Já ao se passar para a voz passiva, o primeiro passo é inverter o objeto, colocando-o no início da frase.
That house was built by the men. (Aquela casa foi construída pelos homens).
Nota-se que, além da inversão do objeto, houve também uma mudança quanto ao tempo verbal da frase. Na voz ativa, o verbo estava no passado simples, e na voz passiva foi acrescentado o passado do verbo “to be” mais o particípio do verbo. Além disso, houve também o acréscimo de by logo após a locução verbal.
Nem todas as frases seguirão o mesmo modelo acima. É preciso, portanto, estar atento ao tempo verbal da frase na voz ativa, para saber em que tempo verbal ela deverá vir na voz passiva. Segue abaixo uma tabela que ilustra os tempos verbais da voz ativa e da voz passiva:

Tempo na voz ativa	Voz passiva	Exemplos
Presente simples	are/ is + particípio	Voz ativa: Bob writes letters. (Bob escreve cartas). Voz Passiva: Letters are written by Bob. (Cartas são escritas por Bob).
Presente contínuo	is/are + being + verbo no particípio	Voz ativa: Bob is writing a letter. (Bob está escrevendo uma carta). Voz passiva: A letter is being written by Bob. (Uma carta está sendo escrita por Bob).
Passado simples	was/were + verbo no particípio	Voz ativa: Bob wrote a letter. (Bob escreveu uma carta). Voz passiva: A letter was written by Bob. (Uma carta foi escrita por Bob).
Passado contínuo	was/were + being + verbo no particípio	Voz ativa: Bob was writing a letter. (Bob estava escrevendo uma carta). Voz passiva: A letter was being written by Bob. (Uma carta estava sendo escrita por Bob).
Futuro simples	will be + verbo no particípio	Voz ativa: Bob will write a letter. (Bob escreverá uma carta). Voz passiva: A letter will be written by Bob. (Uma carta será escrita por Bob).
Presente perfeito	has/have + been + verbo no particípio	Voz ativa: Bob has written letters. (Bob tem escrito cartas). Voz passiva: Letters have been written by Bob. (Cartas têm sido escritas por Bob).
Passado Perfeito	had been + verbo no particípio	Voz ativa: Bob had written letters. (Bob tinha escrito cartas). Voz passiva: Letters had been written by Bob. (Cartas tinham sido escritas por Bob).
Futuro com o “going to”	am/is/are + going to be + verbo no particípio	Voz ativa: Bob is going to write a letter. (Bob escreverá uma carta). Voz passiva: A letter is going to be written by Bob. (Uma carta será escrita por Bob).

Obs.: Quando o sujeito da voz ativa for indeterminado (someone – alguém, people – pessoas), não se coloca o agente da passiva (aquele que sofreu a ação pelo verbo), nem by.
Ex.:
Voz ativa: Someone opened the gate. (Alguém abriu o portão).Voz passiva: The gate was opened. (O portão foi aberto).
Layssa Gabriela Almeida e Silva
Colaboradora Brasil Escola
Licenciada em Letras - Inglês pela Universidade Estadual de Goiás - UEG
Curso de aperfeiçoamento em Inglês pela Zoni Language Centers - Estados Unidos - EUA 

Passive Voice

Use of Passive

Passive voice is used when the focus is on the action. It is not important or not known, however, who or what is performing the action.

Example: My bike was stolen.

In the example above, the focus is on the fact that my bike was stolen. I do not know, however, who did it.

Sometimes a statement in passive is more polite than active voice, as the following example shows:

Example: A mistake was made.

In this case, I focus on the fact that a mistake was made, but I do not blame anyone (e.g. You have made a mistake.).

Form of Passive

Subject + finite form of to be + Past Participle (3rd column of irregular verbs)

Example: A letter was written.

When rewriting active sentences in passive voice, note the following:

§                          the object of the active sentence becomes the subject of the passive sentence

§                          the finite form of the verb is changed (to be + past participle)

§                          the subject of the active sentence becomes the object of the passive sentence (or is dropped)

Examples of Passive

Tense		Subject	Verb	Object
Simple Present	Active:	Rita	writes	a letter.
	Passive:	A letter	is written	by Rita.
Simple Past	Active:	Rita	wrote	a letter.
	Passive:	A letter	was written	by Rita.
Present Perfect	Active:	Rita	has written	a letter.
	Passive:	A letter	has been written	by Rita.
Future I	Active:	Rita	will write	a letter.
	Passive:	A letter	will be written	by Rita.
Hilfsverben	Active:	Rita	can write	a letter.
	Passive:	A letter	can be written	by Rita.

Examples of Passive Level: upper intermediate

Tense		Subject	Verb	Object
Present Progressive	Active:	Rita	is writing	a letter.
	Passive:	A letter	is being written	by Rita.
Past Progressive	Active:	Rita	was writing	a letter.
	Passive:	A letter	was being written	by Rita.
Past Perfect	Active:	Rita	had written	a letter.
	Passive:	A letter	had been written	by Rita.
Future II	Active:	Rita	will have written	a letter.
	Passive:	A letter	will have been written	by Rita.
Conditional I	Active:	Rita	would write	a letter.
	Passive:	A letter	would be written	by Rita.
Conditional II	Active:	Rita	would have written	a letter.
	Passive:	A letter	would have been written	by Rita.

Passive Sentences with Two Objects

Rewriting an active sentence with two objects in passive voice means that one of the two objects becomes the subject, the other one remains an object. Which object to transform into a subject depends on what you want to put the focus on.

	Subject	Verb	Object 1	Object 2
Active:	Rita	wrote	a letter	to me.
Passive:	A letter	was written	to me	by Rita.
Passive:	I	was written	a letter	by Rita.

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As you can see in the examples, adding by Rita does not sound very elegant. That’s why it is usually dropped.

Personal and Impersonal Passive

Personal Passive simply means that the object of the active sentence becomes the subject of the passive sentence. So every verb that needs an object (transitive verb) can form a personal passive.

Example: They build houses. – Houses are built.

Verbs without an object (intransitive verb) normally cannot form a personal passive sentence (as there is no object that can become the subject of the passive sentence). If you want to use an intransitive verb in passive voice, you need an impersonal construction – therefore this passive is called Impersonal Passive.

Example: he says – it is said

Impersonal Passive is not as common in English as in some other languages (e.g. German, Latin). In English, Impersonal Passive is only possible with verbs of perception (e. g. say, think, know).

Example: They say that women live longer than men. – It is said that women live longer than men.

Although Impersonal Passive is possible here, Personal Passive is more common.

Example: They say that women live longer than men. – Women are said to live longer than men.

The subject of the subordinate clause (women) goes to the beginning of the sentence; the verb of perception is put into passive voice. The rest of the sentence is added using an infinitive construction with 'to' (certain auxiliary verbs and that are dropped).

Sometimes the term Personal Passive is used in English lessons if the indirect object of an active sentence is to become the subject of the passive sentence.