PASIVE VOICE

Funciones de la voz pasiva

La voz pasiva se utiliza para mostrar interés por la persona o cosa que es objeto de una acción, en lugar de la persona o cosa que realiza dicha acción. Dicho de otro modo, la persona o cosa más importante pasa a ser el sujeto de la oración, ejemplos:

• The passive voice is used frequently. (es la la voz pasiva la que interesa, no quién la usa.)
• The hotel was built in 1654. ( en este caso quién interesa es el hotel, no quién lo construyó.)
• The castle is being repaired. (El castillo es lo que nos interesa, no quién lo arregla.)

Cuando desconocemos o no queremos mencionar a quién realizó una acción, utilizamos la voz pasiva, ejemplos:

• I noticed that a door had been left open.
• Every year hundred of people are killed on our roads.
• All the biscuits have been eaten.
• My car has been broken!

Se suele utilizar la voz pasiva en textos formales. 

• Our planet is wrapped in a mass of gases.

Utilizamos la preposición 'by' si queremos decir quién o qué realiza la acción.

Cuando sabemos quién realizó la acción y el sujeto nos interesa, siempre es mejor optar por la voz activa. 

• Hamlet was written by Shakespeare
• ET was directed by Spielberg

Formación de la Pasiva
En Inglés, la voz pasiva está compuesta por dos elementos:

la forma apropiada del verbo "to be" + "past participle"

Afirmative:

The hotel was built in 1970.These houses were built in 1899.

Negative:

The hotel wasn't  built  in 1970.

These houses weren't  built  in 1899.

Interrogative:

Was  the  hotel  built in  1970h?Were  these  houses built in 1899?

Interrogative-negative:

Wasn't the house built in 1899?

Weren't these houses built in 1899?

PASSIVE VOICE - 'TO PAINT'

Subject	To 'BE' (conjugado)	Past 'Participle'	Complement
Simple Present :
The school	is	painted	every day.
Present Continuous :
The school	Is being	painted	every day.
Simple Past :
The school	was	painted	every day.
Past Continuous :
The school	was being	painted	every day.
Present Perfect :
The school	has been	painted	every day.
Past Perfect :
The school	had been	painted	every day.
Future :
The school	will be	painted	every day.
Future Continuous :
The school	will be being	painted	every day.
Present Contitional :
The school	would be	painted	every day.
Past Conditional :
The school	would have been	painted	every day.
Infinitive :
The school	must be	painted	every day.
The school	should be	painted	every day.

You can practice here now

Excercise 1
Excercise 2 
Excercise 3
Excercise 4
Excercise 5
Excercise 6
Excercise 7