PASSIVE VOICE

The passive voice is less usual than the active voice. The active voice is the "normal" one

Voz activa lo que interesa es la persona responsable de la acción (agente objeto)
La acción del verbo se enfoca en el sujeto
Morse invented the telegraph

Voz pasiva lo que interesa es el paciente o resultado de la acción. Objeto agente.
La usamos cuando damos más importancia a la acción y no a quien la realiza.
The telegraph was invented by Morse

Se usa "by" para indicar el sujeto que recibe los efectos de la acción
Usamos "by", cuando el agente es evidente, es relevante
No se usa" by" cuando el agente no es importante, lo desconocemos o no lo sabemos con certeza

No podemos usar la voz pasiva con verbos intransitivos como "die", "arrive" o "go". Verbos intransitivos son verbos que no llevan un objeto directo. 
El complemento agente de la pasiva aparece exclusivamente en oraciones con verbos transitivos, siempre y cuando estos estén en VOZ PASIVA, creada por la perífrasis SER+PARTICIPIO.

Aunque, hay algunos verbos, que aún siendo transitivos, no se pueden usar en voz pasiva. Ejercicio

But sometimes we need the passive voice.

1.    Use the passive when you want to talk about

saying who or what does I did the action.

2.    If you also want to mention the person or

thing that did the action (the agent), use by,

e.g. Prison sentences are decided by judges.

However, in the majority of passive sentences

the agent is not mentioned.

Conjugation for the Passive Voice

infinitive		to be washed
simple	present	It is washed.
	past	It was washed.
	future	It will be washed.
	conditional	It would be washed.
continuous	present	It is being washed.
	past	It was being washed.
	future	It will be being washed.
	conditional	It would be being washed.
perfect simple	present	It has been washed.
	past	It had been washed.
	future	It will have been washed.
	conditional	It would have been washed.
perfect continuous	present	It has been being washed.
	past	It had been being washed.
	future	It will have been being washed.
	conditional	It would have been being washed.

¿Cómo distinguir entre la voz pasiva y la voz activa?. click

ejercicios

PASSIVE VOICE
Simple Present	Simple Past
Subject + To be + Participle He repaires the car The car is repaired	Subject + was/were + Participle               The painted the door               The door was painted
Present Continuos	Past Continuos
Is/ are being The trial is being held at the moment.	Was/were being The cinema was being rebuilt when it was set on fire.
Present Perfect	Future
Subject + has/have + Participle            They have phones her            She has been phoned       He has done all the reports       All the reports have been done	Subject +will/must/can/should/be +Participle          The waiter will serve dinner          The dinner will be served by the waiter                                              by + sujeto

Passive Spanish explanations
Passive voice exercises and structures
La voz pasiva
Grammar Passive

OTHER PASSIVE VOICE

infinitive with to            People used to be imprisoned for stealing bread.

infinitive without to      You can be fined for parking on a yellow line.

                                                                                                       

Gerund                            He paid a fine to avoid being sent to jail

IMPERSONAL PASSIVE

IMPERSONAL PASSIVE EXERCISE

it is said that ... , he is thought to ..., Is believed..., is expected... ) etc.

ACTIVE	PASSIVE
1 They say that the company may close. People think that prices will go up. 2 People say the man is in his 40s. The police believe he has left the country. CAREFUL: in passive is HAVE LEFT	It is said, believed... + that + clause It is said that the company may close. It is thought that prices will go up. IS SAID, IS BELIEVED + TO+ INF The man is said to be in his 40s. TO+ HAVE+PARTICIPLE He is believed to have left the country Not  HAS LEFT

2. You can use He, The man, etc. (i.e. the subject of the clause) + is said, believed, etc.

   + to + infinitive (e.g. to be) or perfect infinitive (e.g. to have been).

Referencia presente o futura: infinitivo

Si el verbo de la oración activa hace referencia al presente o al futuro, utilizaremos el infinitivo simple.

The verb in the active sentence: present or future, use TO+ INFINITIVE

ACTIVE: People believe that Mr. Smith owns a lot of land in the south.
PASSIVE: Mr. Smith is believed to own a lot of land in the south.

Referencia pasada: el perfecto infinitivo

Si el verbo de la oración activa hace referencia al pasado, independientemente de que el tiempo verbal sea "simple past", "present perfect" o "past perfect", utilizaremos el infinitivo perfecto.

The verb in the active sentence: past simple, present perfect or past perfect, use TO+ HAVE +PARTICIPLE

ACTIVE: They thought that the prisoners had escaped

PASSIVE: The prisoners were thought to have escaped

Nota: si cualquiera de los tiempos anteriores apareciese en forma continua, nos quedarían las otras dos opciones.

Activa: The bank manager say that Mr.Smith is having finantial difficulties. 

Pasiva: Mr. Smith is said to be having finantial difficulties (Se dice que el Sr. Smith está teniendo - ahora, en estos momentos- dificultades económicas).

Activa: Their parents thought that they were studying English instead of French

Pasiva: They were thought to have been studying English instead of French (se pensaba que ellos habian estado estudiando inglés en vez de francés)

1. Exercises: Voz Pasiva Impersonal III – (Impersonal Passive Voice)
2. Exercises: Voz Pasiva Impersonal V – (Impersonal Passive Voice)
3. Passive Voice with two Objects – Voz Pasiva con dos objetos
4. Passive Voice – Voz Pasiva
5. Ejercicios: Active Voice to Passive Voice (Voz Activa a Voz Pasiva)
6. Ejercicios: Passive Voice II (Voz Pasiva)

Ejercicios
Ejercicios
Ejercicio con diferentes estructuras
TWO OBJECTS EXERCISE
ACTIVE-PASSIVE EXERCISE
ACTIVE-PASSIVE EXERCISE 2
ACTIVE TO PASSIVE EXERCISE