Active and Passive Voice Rules with Formulas, Conversion and Examples

Understanding active and passive voice rules is not simply a matter of memorising a conversion formula, though the active and passive voice rules and formula is certainly important. It is about understanding why voice matters: why some contexts demand the directness of active voice, why scientific and formal writing favours passive, and how the choice of voice shapes the reader’s experience of a sentence. It is also about understanding the rules that govern correctness: which verbs can and cannot be made passive, how pronouns change, how tense is maintained and what the most common errors are.

This page provides the most comprehensive guide to active and passive voice rules available. It covers the definition and core principles, all the English active and passive voice rules with clear explanations, the complete active and passive voice rules and formula, the active and passive voice rules and conversion process, the active and passive voice all rules chart for tenses, common errors and when to choose each voice, supported throughout with active and passive voice rules with examples.

 

Table of Contents

• What is Active and Passive Voice?
• Core Active and Passive Voice Rules
• Active and Passive Voice Rules and Formula
• Active and Passive Voice Rules and Conversion: Step-by-Step
• Active and Passive Voice All Rules Chart: Tenses
• Active and Passive Voice Rules with Examples: All Tenses
• Active and Passive Voice Rules for Modal Verbs
• When to Use Active Voice and When to Use Passive Voice
• Common Errors in Active and Passive Voice
• Practice Exercises on Active and Passive Voice Rules
• Frequently Asked Questions about Active and Passive Voice Rules

 

What is Active and Passive Voice?

Before studying active and passive voice rules, understanding the precise definition of each voice is essential.

Active Voice

In the active voice, the grammatical subject of the sentence performs the action expressed by the verb. The standard word order is Subject (doer) + Verb + Object (receiver).

• The teacher (subject: doer) wrote (verb) a letter (object: receiver).
• The workers (subject: doer) are building (verb) a bridge (object: receiver).

Passive Voice

In the passive voice, the grammatical subject of the sentence receives the action. The original object moves to the subject position, and the verb changes to a form of ‘be’ + past participle. The original subject (the agent) either moves to a ‘by’ phrase or is omitted.

• The papers (new subject: receiver) were corrected (passive verb) by the teacher (agent).
• A letter (new subject: receiver) was written (passive verb) by her (agent).
• A bridge (new subject: receiver) is being built (passive verb) by the workers (agent).

The Core Distinction at a Glance

 

Feature	Active Voice	Passive Voice
Subject	Performs the action	Receives the action
Structure	Subject + Verb + Object	Object (as subject) + Be + Past Participle
Focus	On the doer (agent)	On the receiver of the action
Agent position	Grammatical subject (beginning)	‘By’ phrase (end) or omitted
Typical use	Direct, clear, everyday writing	Formal, scientific, emphasis on result

 

Core Active and Passive Voice Rules

The following are the foundational English active and passive voice rules that govern the use of voice across all tenses, sentence types and contexts. Every other rule on this page is an application or extension of these core principles.

Rule 1: Only Transitive Verbs Can Be Made Passive

A transitive verb is one that takes a direct object. The direct object is essential to passive voice conversion because it becomes the new subject of the passive sentence. Intransitive verbs, which take no object, cannot form a passive sentence.

Transitive (passive possible):

• Active: She wrote a letter. (object: ‘a letter’)

• Passive: A letter was written by her.

Intransitive (passive impossible):

• Active: She arrived. (no object)

• Passive: [cannot be formed]

• Active: He laughed. (no object)

• Passive: [cannot be formed]

This is one of the most important active and passive voice rules: before attempting to form a passive sentence, check that the active sentence has a direct object.

Rule 2: The Direct Object of the Active Sentence Becomes the Subject of the Passive Sentence

This is the structural heart of passive voice formation. Whatever is receiving the action in the active sentence moves to the front of the passive sentence and becomes its grammatical subject.

• Active: The dog bit the man. (object: the man)

• Passive:The man was bitten by the dog. (the man is now the subject)

• Active: She painted the house. (object: the house)

• Passive:The house was painted by her. (the house is now the subject)

Rule 3: The Verb Changes to the Appropriate Form of ‘Be’ + Past Participle

In every passive sentence, the main verb takes the form: auxiliary ‘be’ (in the correct tense form) + past participle of the main verb. The form of ‘be’ carries the tense; the past participle provides the action.

• Active: She writes a letter. (simple present active)

• Passive: A letter is written by her. (is = present ‘be’; written = past participle)

• Active: She wrote a letter. (simple past active)

• Passive: A letter was written by her. (was = past ‘be’; written = past participle)

• Active: She has written a letter. (present perfect active)

• Passive: A letter has been written by her. (has been = present perfect ‘be’; written = past participle)

Rule 4: The Subject of the Active Sentence Becomes the Agent in a ‘By’ Phrase

The original subject (the performer of the action) moves to the end of the sentence in a prepositional phrase beginning with ‘by’.

• Active: The teacher corrected the papers.

• Passive: The papers were corrected by the teacher.

• Active: She will complete the project.

• Passive: The project will be completed by her.

Rule 5: The Pronoun Must Change Form When Moving to the ‘By’ Phrase

When the subject of an active sentence is a pronoun, it changes from its subject (nominative) form to its object (accusative) form when it moves to the ‘by’ phrase in the passive sentence.

 

Subject pronoun (active)	Object pronoun (passive ‘by’ phrase)
I	by me
you	by you
he	by him
she	by her
it	by it
we	by us
they	by them

 

• Active: She cooked the meal.

• Passive: The meal was cooked by her. (she → her)

• Active: They have completed the project.

• Passive: The project has been completed by them. (they → them)

• Active:I wrote the report.

• Passive: The report was written by me. (I → me)

Rule 6: Tense is Preserved in the Passive through the Form of ‘Be’

The tense of the original active sentence is never lost in conversion. It is carried by the auxiliary verb ‘be’, which takes the appropriate tense form. The past participle itself does not change to indicate tense.

• Active (simple past): She wrote the letter.

• Passive (simple past): The letter was written by her. (past tense shown by ‘was’)

• Active (present perfect): She has written the letter.

• Passive (present perfect): The letter has been written by her. (present perfect shown by ‘has been’)

• Active (future): She will write the letter.

• Passive (future): The letter will be written by her. (future shown by ‘will be’)

Rule 7: The ‘By’ Phrase is Often Omitted

In many passive sentences, the ‘by’ phrase is dropped entirely. This is not an error: it is a feature of passive voice that makes it useful. The agent is omitted when:

• The agent is unknown: The window was broken. (we do not know who broke it)

• The agent is obvious from context: The criminal was arrested. (obviously by the police)

• The agent is unimportant or irrelevant: The results will be announced tomorrow.

• The speaker deliberately avoids naming the agent: Mistakes were made.

Rule 8: Number Agreement Must Be Maintained

The form of ‘be’ in the passive sentence must agree with the new subject (the original object) in number.

• Active: She writes a letter. (singular object)
• Passive: A letter is written by her. ('is' agrees with singular 'a letter')
• Active: She writes letters. (plural object)
• Passive: Letters are written by her. ('are' agrees with plural 'letters')
• Active: He repaired the car. (singular object)
• Passive: The car was repaired by him. ('was' with singular)
• Active: He repaired the cars. (plural object)
• Passive: The cars were repaired by him. ('were' with plural)

Rule 9: The Past Participle Must Be Used, Not the Simple Past Form

This is one of the most commonly violated active and passive voice rules. The passive construction requires the past participle (V3), not the simple past form (V2).

• Incorrect: The letter was wrote by her. ('wrote' is simple past)
• Correct: The letter was written by her. ('written' is past participle)
• Incorrect: The book was took from the shelf.
• Correct: The book was taken from the shelf.
• Incorrect: The window was broke by him.
• Correct: The window was broken by him.

Rule 10: Active Voice is Not 'Better' Than Passive Voice

A common misconception is that active voice is always correct and passive voice is always to be avoided. This is not accurate. Both voices serve important and distinct purposes. The active and passive voice rules that govern when to use each voice are not about quality but about appropriateness: the right voice for the right context.

 

Active and Passive Voice Rules and Formula

The active and passive voice rules and formula provides the systematic structure for every passive construction. Once the formula is understood, conversion becomes a reliable and consistent process.

The Master Formula

• Active: S + V (tense marker) + O

• Passive: O (as new S) + appropriate form of 'be' (tense marker) + Past Participle + (by + original S)

The formula components explained:

• S = the grammatical subject of the sentence (who or what performs the action)
• V = the verb in its active form
• O = the direct object (who or what receives the action)
• be = auxiliary 'be' in the correct tense form
• Past Participle = V3 form of the main verb
• by + original S = the agent phrase (often omitted)

Formula Applied across Voices

 

Component	Active	Passive
Subject	Doer of action	Receiver of action (original object)
Verb	Tense-marked active verb	Appropriate 'be' + past participle
Object/Agent	Receiver of action	'by' + original doer (or omitted)

 

How to determine the correct form of 'be':

The appropriate form of 'be' is determined by the tense of the original active sentence.

 

Tense	Form of 'be' in passive
Simple present	is / are
Present continuous	is being / are being
Present perfect	has been / have been
Simple past	was / were
Past continuous	was being / were being
Past perfect	had been
Simple future	will be
Future perfect	will have been
Modal present	modal + be
Modal perfect	modal + have been

 

Active and Passive Voice Rules and Conversion: Step-by-Step

The active and passive voice rules and conversion process is most reliable when followed as a series of clear steps. The following step-by-step guide applies to every active sentence in every tense.

The Six-Step Conversion Process

Step 1: Identify the subject, verb and direct object of the active sentence.

• Sentence: The committee approved the proposal.
• Subject: 'The committee'
• Verb: 'approved' (simple past)
• Object: 'the proposal'

Step 2: Move the direct object to the subject position.

• New subject: 'The proposal'

Step 3: Identify the tense and write the correct form of 'be'.

• Tense: simple past → 'be' form: 'was'

Step 4: Write the past participle of the main verb.

• Past participle of 'approve': 'approved'

Step 5: Write 'was approved' as the passive verb.

• 'The proposal was approved'

Step 6: Move the original subject to a 'by' phrase (or omit if not needed).

• 'The proposal was approved by the committee.'

Conversion Worked Examples

Example 1:

• Active: 'She teaches English.'
• Step 1: Subject = She; Verb = teaches (simple present); Object = English
• Step 2: New subject = English
• Step 3: Simple present → is/are; 'English' is singular → 'is'
• Step 4: Past participle of 'teach' = 'taught'
• Step 5: Passive verb = 'is taught'
• Step 6: Agent = 'by her' (she → her)
• Passive: 'English is taught by her.'

Example 2:

• Active: 'They have completed the project.'
• Step 1: Subject = They; Verb = have completed (present perfect); Object = the project
• Step 2: New subject = the project
• Step 3: Present perfect → has/have been; 'the project' is singular → 'has been'
• Step 4: Past participle of 'complete' = 'completed'
• Step 5: Passive verb = 'has been completed'
• Step 6: Agent = 'by them' (they → them)
• Passive: 'The project has been completed by them.'

Example 3:

• Active: 'The workers were repairing the road.'
• Step 1: Subject = The workers; Verb = were repairing (past continuous); Object = the road
• Step 2: New subject = the road
• Step 3: Past continuous → was/were being; 'the road' is singular → 'was being'
• Step 4: Past participle of 'repair' = 'repaired'
• Step 5: Passive verb = 'was being repaired'
• Step 6: Agent = 'by the workers'
• Passive: 'The road was being repaired by the workers.'

 

Active and Passive Voice All Rules Chart: Tenses

The following active and passive voice all rules chart provides a complete at-a-glance reference for all major tenses, covering the formula, active example and passive example for each.

 

Tense	Active Formula	Passive Formula	Active Example	Passive Example
Simple Present	S + V(s/es) + O	O + is/are + V3	She writes a letter.	A letter is written by her.
Present Continuous	S + is/are + V-ing + O	O + is/are being + V3	She is writing a letter.	A letter is being written by her.
Present Perfect	S + has/have + V3 + O	O + has/have been + V3	She has written a letter.	A letter has been written by her.
Simple Past	S + V2 + O	O + was/were + V3	She wrote a letter.	A letter was written by her.
Past Continuous	S + was/were + V-ing + O	O + was/were being + V3	She was writing a letter.	A letter was being written by her.
Past Perfect	S + had + V3 + O	O + had been + V3	She had written a letter.	A letter had been written by her.
Simple Future	S + will + V1 + O	O + will be + V3	She will write a letter.	A letter will be written by her.
Future Perfect	S + will have + V3 + O	O + will have been + V3	She will have written a letter.	A letter will have been written by her.
Modal (present)	S + Modal + V1 + O	O + Modal + be + V3	She should write a letter.	A letter should be written by her.
Modal (perfect)	S + Modal + have + V3 + O	O + Modal + have been + V3	She should have written a letter.	A letter should have been written by her.

 

Key: V1 = base form, V2 = past tense, V3 = past participle, S = subject, O = object

 

Active and Passive Voice Rules with Examples: All Tenses

The following section provides complete active and passive voice rules for all tenses with examples, with multiple examples per tense.

Simple Present

Formula: is/are + past participle

• She teaches the class. → The class is taught by her.
• He repairs cars. → Cars are repaired by him.
• They clean the office every day. → The office is cleaned by them every day.

Present Continuous

Formula: is/are being + past participle

• She is teaching the class. → The class is being taught by her.
• They are building a school. → A school is being built by them.
• He is reading the newspaper. → The newspaper is being read by him.

Present Perfect

Formula: has/have been + past participle

• She has submitted the form. → The form has been submitted by her.
• They have completed the work. → The work has been completed by them.
• He has announced the results. → The results have been announced by him.

Simple Past

Formula: was/were + past participle

• She wrote the letter. → The letter was written by her.
• They built the bridge. → The bridge was built by them.
• He taught the students. → The students were taught by him.

Past Continuous

Formula: was/were being + past participle

• She was teaching the class. → The class was being taught by her.
• They were repairing the road. → The road was being repaired by them.
• He was reading a book. → A book was being read by him.

Past Perfect

Formula: had been + past participle

• She had submitted the form. → The form had been submitted by her.
• They had completed the project. → The project had been completed by them.
• He had written the report. → The report had been written by him.

Simple Future

Formula: will be + past participle

• She will write a letter. → A letter will be written by her.
• They will complete the project. → The project will be completed by them.
• He will announce the results. → The results will be announced by him.

Future Perfect

Formula: will have been + past participle

• She will have written the report. → The report will have been written by her.
• They will have completed the work. → The work will have been completed by them.

 

Active and Passive Voice Rules for Modal Verbs

Modal verbs have their own active and passive voice rules and formula, which applies uniformly across all modals.

Modal Present Passive Formula

• Active: Subject + Modal + Base form + Object
• Passive: Object + Modal + be + Past Participle + (by + Subject)

 

Modal	Active Example	Passive Example
can	She can solve the problem.	The problem can be solved by her.
could	He could repair the car.	The car could be repaired by him.
may	She may write the letter.	The letter may be written by her.
might	They might cancel the event.	The event might be cancelled by them.
must	She must submit the form.	The form must be submitted by her.
should	He should complete the work.	The work should be completed by him.
would	She would bake a cake.	A cake would be baked by her.
ought to	They ought to repair the road.	The road ought to be repaired by them.
need to	She needs to sign the form.	The form needs to be signed by her.
have to	They have to complete the task.	The task has to be completed by them.

 

Modal Perfect Passive Formula

• Active: Subject + Modal + have + Past Participle + Object
• Passive: Object + Modal + have been + Past Participle + (by + Subject)

Examples:

• Active: She should have submitted the report.
• Passive: The report should have been submitted by her.
• Active: They might have cancelled the event.
• Passive: The event might have been cancelled by them.
• Active: He must have written the letter.
• Passive: The letter must have been written by him.
• Active: We could have prevented the accident.
• Passive: The accident could have been prevented by us.

 

When to Use Active Voice and When to Use Passive Voice

Understanding active and passive voice rules fully requires knowing when each voice is the better choice. This is not simply a grammatical question but a question of communication purpose and context.

Use Active Voice When

1. Clarity and directness are priorities

Active voice is shorter and more direct. It makes clear who is doing what without requiring the reader to work backward from the passive construction.

• Active: The committee approved the budget. (direct; clear agent)
• Passive: The budget was approved by the committee. (less direct)

2. The agent is the most important element

When who is doing the action matters most, active voice foregrounds the agent.

• Active: Einstein developed the theory of relativity.
• Passive: The theory of relativity was developed by Einstein. (Einstein is less prominent)

3. Writing narrative, creative or conversational text

Active voice gives narrative a sense of momentum and immediacy.

• Active: She opened the door. She stepped into the corridor. She saw him waiting.

4. Giving instructions

Instructions should be direct. Active or imperative voice works best.

• Active: Submit your application by Friday.
• Passive: Applications should be submitted by Friday. (acceptable but less direct)

Use Passive Voice When

1. The agent is unknown

When we do not know who performed the action, passive voice is the natural choice.

• The window was broken last night. (unknown who broke it)
• The document has been altered. (unknown who altered it)

2. The agent is obvious or unimportant

• The criminal was arrested yesterday. (obviously by the police; stating this is unnecessary)
• The results will be announced on Monday. (who announces them is irrelevant)

3. The receiver of the action is more important than the doer

• Three students were injured in the accident. (the students matter more than who caused the injury)
• The new hospital was opened last week. (the hospital matters; who opened it is secondary)

4. Formal, scientific or academic writing

Scientific writing uses passive to maintain objectivity and an impersonal tone.

• The samples were heated to 100 degrees Celsius.
• The data were collected over a six-month period.
• The hypothesis was tested using a controlled experiment.

5. Deliberately avoiding naming an agent (diplomatic or strategic omission)

• Mistakes were made. (avoids assigning specific blame)
• It has been decided that the project will be postponed. (no specific decision-maker named)

 

Common Errors in Active and Passive Voice

 

Error 1: Using the Simple Past Form instead of the Past Participle

This is the single most common error in passive voice construction. The passive requires V3 (past participle), not V2 (simple past).

• Incorrect: The letter was wrote by her.
• Correct: The letter was written by her.
• Incorrect: The car was drove by him.
• Correct: The car was driven by him.
• Incorrect: The report was gave to the manager.
• Correct: The report was given to the manager.

Error 2: Using the Wrong Form of 'Be' (Number Agreement Error)

The form of 'be' must agree with the new subject (the original object) in number.

• Incorrect: The letters was written by her. ('letters' is plural: 'were')
• Correct: The letters were written by her.
• Incorrect: The results is announced every year. ('results' is plural: 'are')
• Correct: The results are announced every year.

Error 3: Failing to Change the Pronoun

When the active subject is a pronoun, it must change to its object form in the passive 'by' phrase.

• Incorrect: The letter was written by she.
• Correct: The letter was written by her.
• Incorrect: The project was completed by they.
• Correct: The project was completed by them.

Error 4: Changing the Tense During Conversion

The passive sentence must preserve the tense of the original active sentence.

• Active (simple past): She wrote the letter.
• Incorrect passive: The letter is written by her. (tense changed to present)
• Correct passive: The letter was written by her.

Error 5: Attempting to Make Intransitive Verbs Passive

Intransitive verbs (those with no direct object) cannot be made passive.

• Incorrect: The race was run by her. (if 'ran' was used intransitively: 'She ran.')
• Correct: She ran. (no passive possible for intransitive use)

Error 6: Using 'By' When the Agent Should Be Omitted

In natural writing, an obvious or irrelevant agent should be omitted. Retaining it produces an awkward, over-explained sentence.

• Awkward: The criminal was arrested by the police yesterday. (obviously by the police)
• Natural: The criminal was arrested yesterday.

Error 7: Incorrect Imperative Passive

• Incorrect: The door should be opened. (for an imperative: this is not a command)
• Correct imperative passive: Let the door be opened.

Error 8: Treating 'Get' + Past Participle as Passive (Confusion)

'Get' + past participle (get broken, get hurt, get fired) is an informal passive construction. It functions similarly to 'be' + past participle but is less formal and often implies a less controlled or unexpected event.

• She got hurt in the accident. (informal passive)
• She was hurt in the accident. (standard passive)

Both are grammatically correct but differ in formality and connotation. 'Get' passives are not appropriate in formal academic writing.

 

Practice Exercises on Active and Passive Voice Rules

A. Read each sentence and answer the questions below.

Sentence A: 'The scientist discovered a new compound.'

Sentence B: 'A new compound was discovered by the scientist.'

Sentence C: 'The results were announced yesterday.'

Sentence D: 'She arrived early.'

Sentence E: 'The windows are cleaned every Monday.'

1. Which sentences are in active voice?
2. Which sentences are in passive voice?
3. Which active sentence cannot be made passive? Why?
4. In sentence C, why is there no 'by' phrase?
5. What is the agent in sentence B, and what pronoun rule applies?

B. Convert each sentence as instructed. Identify the tense and use the correct passive formula.

1. 'She teaches English every day.' → Passive (simple present)
2. 'They are building a new school.' → Passive (present continuous)
3. 'She has completed the assignment.' → Passive (present perfect)
4. 'He wrote the report.' → Passive (simple past)
5. 'They were painting the building.' → Passive (past continuous)
6. 'She had submitted the form.' → Passive (past perfect)
7. 'He will announce the results.' → Passive (simple future)
8. 'They will have completed the project by Friday.' → Passive (future perfect)
9. 'She should write the letter.' → Passive (modal: should)
10. 'He must have broken the window.' → Passive (modal perfect)

C. Convert each passive sentence to active voice. Identify the tense in each.

1. 'The cake was baked by her.'
2. 'English is taught by the professor.'
3. 'The project has been completed by the team.'
4. 'The road is being repaired by the workers.'
5. 'The letter had been written by him before she arrived.'
6. 'The results will be announced by the principal.'
7. 'The car can be repaired by the mechanic.'
8. 'The match was cancelled by the organisers.'
9. 'A new hospital will have been built by next year.'
10. 'The students were being taught when the bell rang.'

D. Each sentence contains one error in active or passive voice construction. Identify the error and correct it.

1. 'The letter were written by her.'
2. 'The book was took from the shelf.'
3. 'The project was completed by they.'
4. Active: 'She wrote the report.' → Passive: 'The report is written by her.'
5. 'The results is announced every Monday.'
6. 'The door was broken by she.'
7. 'The meal was cook by the chef.'
8. 'A new law have been passed by the government.'
9. 'Close the window.' → Passive: 'The window should be closed.' (imperative)
10. 'The students were taught English by the teacher. (no error: identify which rule this correctly follows)'

E. For each context below, decide whether active or passive voice is more appropriate. Write one sentence in the appropriate voice and explain your choice.

1. A scientific report describing how a sample was tested.
2. A news headline about a championship victory.
3. A sentence reporting that someone broke into a house last night but the culprit is unknown.
4. A formal announcement that a meeting has been scheduled.
5. A narrative story describing a character opening a door.
6. A public statement that avoids naming who made a controversial decision.
7. A sentence in which the teacher's identity as the one giving the marks is the important information.
8. A process description explaining how a product is manufactured.