How to Understand Active and Passive Voice

Active and Passive Voice

There are two ways to express an action of a subject in relation to its object

• • Active voice
• • Passive voice

In “active voice” subject acts upon object, while in “passive voice” object is acted upon by subject. It can also be said, in “active voice” subject does a work on object, while in “passive voice” object is worked on by subject. The normal structure of an active voice sentence is subject+verb+object but in passive the normal structure of sentence is reversed according to certain rules and becomes like object+verb+subject. The real meaning of a sentence does not change if the sentence is expressed either by active voice or by passive voice. The active voice is mostly used in writing because it gives a direct and more concise meaning. Passive voice is used sometimes due to the following reasons.

1. When intentionally hiding the subject of sentence. For example, a student who failed in exam might say, some chapters were not studied.
   Another example. Women were not treated as equals
2. When passive voice better explain thought of sentence. For example, to say, cloth is sold in yards, is more meaningful than to say, Shop keepers sell cloth in yards.
3. When passive voice better emphasizes the main though of the sentence. For example, a man who is being teased by another person might say in anger, “you will be beaten by me”
4. When subject is not exactly known. For example, His watch was stolen. It is not known that who stole his watch, the subject (thief) is not exactly known so it is better to use passive voice for such sentence.There are certain rules for expressing a thought in passive voice or for changing a sentence from active voice to passive voice.

Fundamental Rules for changing from active voice to passive voice

1. The places of subject and object are interchanged i.e. the object shifts to the place of subject and subject shifts to the place of object in passive voice.

Example.
Active voice: I write a letter.
Passive voice: I letter is written by me.
Subject (I) of sentence shifted to the place of object (letter) and object (letter) shifted to the place of subject (I) in passive voice.

2. Sometimes subject of sentence is not used in passive voice. Subject of sentence can be omitted in passive voice, if without subject it can give enough meaning in passive voice.

Examples.
Passive voice: cloth is sold in yards

3. 3rd form of verb (past participle) is always used as main verb in sentences of passive voice for all tenses. Base form of verb or present participle will be never used in passive voice.
   The word “by” is used before subject in sentences in passive voice.

Example.
Active voice: He sings a song.
Passive voice: A song is sung by him.

4. The word “by” is not always used before subject in passive voice. Sometimes words “with, to, etc” may also be used before subject in passive voice.
   Examples.
   Active voice: The water fills the tub.
   Passive voice: The tub is filled with water.
   Active voice:  He knows me.
   Passive voice: I am known to him.
5. Auxiliary verbs are used passive voice according to the tense of sentence.

PASSIVE VOICE FOR ALL TENSES RULES

• The places of subject and object in sentence are inter-changed in passive voice.
• 3rd form of verb (past participle) will be used only (as main verb) in passive voice.
• Auxiliary verbs for each tense are given below in the table.

Present Simple Tense (passive Voice) Auxiliary verb in passive voice: am/is/are
Active voice: He sings a song. He does not sing a song.Does he sing a song?	Passive voice: A song is sung by him. A song is not sung by him. Is a song sung by him?

Present Continuous Tense (passive Voice) Auxiliary verb in passive voice: am being/is being/are being
Active voice: I am writing a letter I am not writing a letter. Am I writing a letter?	Passive voice: A letter is being written by me. A letter is not being written by me. Is a letter being written by me?

Present Perfect Tense (passive Voice) Auxiliary verb in passive voice: has been/have been
Active voice: She has finished his work She has not finished her work. Has she finished her work?	Passive voice: Her work has been finished by her. Her work has not been finished by her. Has her work been finished by her?

Past Simple Tense (passive Voice) Auxiliary verb in passive voice: was/were
Active voice: I killed a snake I did not kill a snake. Did I kill a snake?	Passive voice: A snake was killed by me. A snake was not killed by me. Was a snake killed by me?

Past Continuous Tense (Passive Voice) Auxiliary verb in passive voice: was being/were being
Active voice: He was driving a car. He was not driving a car. Was he driving a car?	Passive voice: A car was being driven by him. A car was not being driven by him. Was a car being driven by him?

Past Perfect Tense (Passive Voice) Auxiliary verb in passive voice: had been
Active voice: They had completed the assignment. They had not completed the assignment. Had they completed the assignment?	Passive voice: The assignment had been completed by them. The assignment had not been complete by them. Had the assignment been completed by them?

Future Simple Tense (Passive Voice) Auxiliary verb in passive voice: will be
Active voice: She will buy a car. She will not buy a car. Will she buy a car?	Passive voice: A car will be bought by her. A car will not be bought by her. Will a car be bought by her?

Future Perfect Tense (passive Voice) Auxiliary verb in passive voice: will have been
Active voice: You will have started the job. You will have not started the job. Will you have started the job?	Passive voice: The job will have been started by you. The job will not have been started by you. Will the job have been started by you?

Note: The following tenses cannot be changed into passive voice.

1. Present perfect continuous tense
2. Past perfect continuous tense
3. Future continuous tense
4. Future perfect continuous tense
5. Sentence having Intransitive verbs

Fundamental Rules

• The places of subject and object in sentence are inter-changed in passive voice.
• 3rd form of verb (past participle) will be used only (as main verb) in passive voice.
• Auxiliary verbs for each tense are given below in the table.

Passive voice for Present/Future Modals
“CAN, MAY, MIGHT, SHOULD, MUST, OUGHT TO”

• The places of subject and object in sentence are inter-changed in passive voice.
• 3rd form of verb (past participle) will be used only (as main verb) in passive voice.
• To change sentences having present/future modal into passive voice, auxiliary verb “be” is added after modal in sentence.

Passive voice for Present/Future Modals  “CAN, MAY, MIGHT, SHOULD, MUST, OUGHT TO” Auxiliary verb in passive voice: be
Active voice: CAN She can play a violin. She cannot play a violin. Can she play a violin?	Passive voice: CAN BE A violin can be played by her. A violin cannot be played by her. Can a violin be played by her?
Active voice: MAY I may buy the computer. I may not buy the computer. May I buy the computer?	Passive voice: MAY BE The computer may be bought by me. The computer may not be bought by me. May the computer be bought by me?
Active voice: MIGHT Guests might play chess. Guests might not play chess.	Passive voice: MIGHT BE Chess might be played by guests. Chess might not be played guests.
Active voice: SHOULD Students should study all lessons. Students should not study all lessons. Should students study all lessons?	Passive voice: SHOULD BE All lessons should be studied by students. All lessons should not be studied by students. Should all lessons be studied by students?
Active voice: MUST You must learn the test-taking strategies. You must not learn the test-taking strategies.	Passive voice: MUST BE Test-taking strategies must be learnt by you. Test-taking strategies must not be learned by you.
Active voice: OUGHT TO They ought to take the examination.	Passive voice: OUGHT TO BE The examination ought to be taken by them.

Passive voice of imperative sentences

                               (command and request)

A sentence which expresses command or request or advice is called imperative sentence.

For example,

      Open the door.
      Turn off the television.
       Learn your lesson.

For changing these sentences in to passive voice, auxiliary verb “be” is used. The word “Let” is added before sentence in passive voice. Auxiliary verb “be” is added after object in sentence in passive voice. Main verb (base form) of imperative sentence is changed to 3rd form of verb (past participle) in passive voice. For best understand read the following examples.

Examples 

Passive voice of “Imperative Sentences”
Active Voice	Passive Voice
Open the door.	Let the door be opened.
Complete the work.	Let the worked be completed.
Turn off the television.	Let the television be tuned off.
Learn your lesson.	Let your lesson be learnt.
Kill the snake.	Let the snake be killed.
Punish him.	Let him be punished.
Speak the truth.	Let the truth be spoken.
Help the poor.	Let the poor be helped.
Revise your book.	Let your book be revised.
Clean your room.	Let your room be cleaned.

Sentences which cannot be changed into passive voice

Transitive and intransitive verb

A verb can be either transitive or intransitive. A transitive verb needs an object (in sentence) to give complete meaning while intransitive verb does need an object (in sentence) to give complete meaning. 
For example,

Transitive verb.
      He sent a letter.
  (Send is a transitive verb and it needs an object i.e. letter to express full meaning.)

Intransitive Verb.
       He laughs.
      (Laugh is an intransitive verb and it does not need object for expressing full meaning.)
    e.g. Sleep, go, reach, sit, die, are examples of intransitive verbs.
 Intransitive verb cannot be changed into passive voice
The sentences having intransitive verbs (belonging to any tense) cannot be changed into passive voice. The reason is that there is not any object in such sentences and without object of sentence passive voice is not possible.

A sentence can be changed into passive voice if it has subject and object. Sometimes subject may not be written in passive voice but it does not mean that it has no subject. Such sentences have subject but the subject is so common or familiar or known that if even it is not written in passive voice, it gives full meaning.
For example
Cloth is sold in yards.   

The following tenses can also not be changed into passive voice.

1. Present perfect continuous tense
2. Past perfect continuous tense
3. Future continuous tense
4. Future perfect continuous tense