Passive Sentence

In the passive sentence, the object of an active verb becomes the subject of the passive verb.Only transitive verbs are used in the passive.
Intransitive verbs such as happen, sleep, come and seem cannot be used in the passive.

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)

Agent
In a passive clause, we usually use a phrase beginning with by if we want to mention the agent - the person or thing that does the action, or that causes what happens.If you want to change an active sentence which has two objects into its passive forms, there are two ways:
1. Make its indirect object into the subject of the passive sentence.
2. Make its direct object into the subject of the passive sentence.Pattern: be + past participle

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.
The Generic Structure/Formula :

* Active : S + Vactive + O
* Passive : O + to be + V3 + by + S

Passive Voice in Tenses :
1. Simple Present Tense
· Active : V1(es/s)
· Passive : To be(is, am, are) + V3
2. Past tense
· Active : V2(ed)
· Passive : To be(was, were) + V3
3. Past Continous Tense
· Active : To be(is, am, are) + Ving
To be(was, were) + Ving
· Passive : To be(is, am, are) + Being V3
To be(was, were) + Being V3
4. Present Perfect Continous Tense
· Active : been + Ving
· Passive : been + being V3
5. Future Tense
· Active : Be + Ving
· Passive : Be + being V3

Example:
- The boy are listening to a story.

The story was being told by grandfather

- Snow white eats a poisonous apple
A poisonous apple is eaten by snow white

- Snow white is eating a poisonous apple
A poisonous apple is being eaten by snow white

- Snow white has eaten a poisonous apple
A poisonous apple has been eaten by snow white

- Snow white ate a poisonous apple
A poisonous apple was eaten by snow white

- Snow white was eating a poisonous apple
A poisonous apple was being eaten by snow white

- Snow white had eaten a poisonous apple
A poisonous apple had been eaten by snow white

- Snow white will eat a poisonous apple
A poisonous apple will be eaten by snow white

- Snow white is going to eat a poisonous apple
A poisonous apple is going to be eaten by snow white

- Snow white will have eaten a poisonous apple
A poisonous apple will have been eaten by snow white 

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

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.

. 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.