Change of Voice
Active to passive and vice versa
Change of Voice, also known as Active and Passive Voice transformation, is a fundamental grammar concept frequently tested in aptitude examinations. It involves converting sentences from the active form (where the subject performs the action) to the passive form (where the subject receives the action), while maintaining the original meaning and tense of the sentence.
Key Concepts
Understanding Active Voice
In Active Voice, the grammatical subject of the sentence performs the action expressed by the verb. The structure follows: Subject (doer) + Verb + Object (receiver). Active voice creates direct, clear, and concise sentences. Example: 'The chef prepares the meal.' Here, 'the chef' (subject) is doing the action of preparing, and 'the meal' (object) receives the action.
Understanding Passive Voice
In Passive Voice, the grammatical subject receives the action rather than performing it. The structure follows: Object (receiver) + form of 'be' + Past Participle + (by + Subject/doer). The doer can be omitted when unknown or unimportant. Example: 'The meal is prepared by the chef.' Here, 'the meal' becomes the subject receiving the action, while 'the chef' (the actual doer) follows 'by'.
Tense Preservation Rule
When converting between voices, the tense of the original sentence must be preserved. The tense is carried by the 'be' verb in passive constructions. For example, 'She writes letters' (Present Simple) becomes 'Letters are written by her' (still Present Simple). Similarly, 'They built the house' (Past Simple) becomes 'The house was built by them' (still Past Simple).
Omission of the 'By' Phrase
The 'by' phrase (indicating who performed the action) is optional in passive voice. It is omitted when: the doer is unknown ('The car was stolen'), the doer is obvious or unimportant ('The thief was arrested'), or when the doer is general ('English is spoken here'). When present, personal pronouns change form: I->me, he->him, she->her, we->us, they->them.
Intransitive Verbs Cannot Be Passivized
Only transitive verbs (verbs that take a direct object) can be converted to passive voice. Intransitive verbs like 'arrive', 'sleep', 'happen', 'die', 'fall', 'go', 'come', 'exist' cannot form passive constructions because there is no object to become the subject. Example: 'He slept peacefully' has no passive form because 'slept' is intransitive.
Special Cases and Exceptions
Certain verb types have specific passive rules: (1) Verbs with two objects (give, send, tell, offer) can form two passive versions: 'They gave me a book' -> 'I was given a book' or 'A book was given to me'. (2) Complex objects with infinitives: 'They made him leave' -> 'He was made to leave'. (3) Phrasal verbs keep their particles: 'She turned down the offer' -> 'The offer was turned down by her'. (4) Quasi-passive verbs (sell, wash, read, write, open, shut, smell, taste, feel) can use active form with passive meaning: 'The book sells well'.
Solved Examples
Problem 1:
Convert to Passive Voice: The teacher explains the lesson.
Step 1: Identify components - Subject: The teacher, Verb: explains (Present Simple), Object: the lesson.
Step 2: Make the object the new subject: The lesson.
Step 3: Determine correct 'be' verb form for Present Simple singular: is.
Step 4: Use past participle of explain: explained.
Step 5: Add 'by + subject' (converting 'the teacher' to object pronoun is optional, keeping as 'the teacher').
Passive: The lesson is explained by the teacher.
Problem 2:
Convert to Active Voice: The window was broken by the ball.
Step 1: Identify passive components - Subject (receiver): The window, Be verb: was, Past participle: broken, By phrase: by the ball (doer).
Step 2: Make the doer ('the ball') the new subject.
Step 3: Determine original tense from 'was broken': Past Simple.
Step 4: Convert past participle to Past Simple active verb: broke.
Step 5: Make original subject ('the window') the new object.
Active: The ball broke the window.
Problem 3:
Convert to Passive Voice: They have completed the project on time.
Step 1: Identify components - Subject: They, Verb: have completed (Present Perfect), Object: the project.
Step 2: Make the object the new subject: The project.
Step 3: Apply Present Perfect passive structure: has/have + been + V3.
Step 4: 'The project' is singular, so use 'has been completed'.
Step 5: Add 'by them' (converting 'they' to 'them').
Passive: The project has been completed by them.
Note: 'on time' remains unchanged as it's an adverbial phrase.
Problem 4:
Convert to Passive Voice: We must finish this work today.
Step 1: Identify components - Subject: We, Verb: must finish (modal), Object: this work.
Step 2: Apply modal passive structure: modal + be + V3.
Step 3: Make object the subject: This work.
Step 4: Combine: must + be + finished.
Step 5: Add 'by us' (converting 'we' to 'us').
Passive: This work must be finished by us today.
Note: The time expression 'today' maintains its position at the end or beginning.
Tips for Success
- Always preserve the tense of the original sentence when converting voices. The tense is indicated by the form of 'be' in passive constructions.
- Remember that only transitive verbs (verbs with direct objects) can be converted to passive voice. Intransitive verbs cannot form passives.
- When converting to passive, personal pronouns in the subject position change to object form in the 'by' phrase: I->me, he->him, she->her, we->us, they->them.
- The past participle (V3 form) is used in all passive constructions regardless of tense. This is the key identifying feature of passive voice.
- Verbs with two objects (give, send, offer, tell, show) can form two different passive versions. Either object can become the subject of the passive sentence.
- In sentences with modal verbs (can, could, may, might, must, should, would), the passive structure is: modal + be + past participle (for simple modals) or modal + have + been + past participle (for modal perfect).
- Phrasal verbs must keep their particles together when converted to passive: 'They called off the meeting' -> 'The meeting was called off.'
- Quasi-passive constructions (where active form has passive meaning) often appear with verbs like sell, wash, read, write, open, and feel: 'This fabric washes easily' means 'This fabric is easily washable'.
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