Concept
Voice indicates whether the subject of a sentence performs the action (Active Voice) or receives the action (Passive Voice).
- Active Voice: The subject does the action. — "The cat caught the mouse."
- Passive Voice: The subject receives the action. — "The mouse was caught by the cat."
Basic Conversion Formula:
Active: Subject + Verb + Object
Passive: Object (becomes subject) + be + V3 (past participle) + by + Subject (becomes agent)
BCS tests voice change in two ways: (1) convert a given sentence, and (2) identify which sentence is in passive/active voice. Special constructions like quasi-passive, double objects, and complex sentences appear frequently.
Key Rules
Voice Change by Tense — Complete Table
| Tense |
Active |
Passive |
| Simple Present |
He writes a letter |
A letter is written by him |
| Present Continuous |
He is writing a letter |
A letter is being written by him |
| Present Perfect |
He has written a letter |
A letter has been written by him |
| Simple Past |
He wrote a letter |
A letter was written by him |
| Past Continuous |
He was writing a letter |
A letter was being written by him |
| Past Perfect |
He had written a letter |
A letter had been written by him |
| Simple Future |
He will write a letter |
A letter will be written by him |
| Future Perfect |
He will have written a letter |
A letter will have been written by him |
| Modal (can/must/should) |
He can write a letter |
A letter can be written by him |
Note: There is no passive for Present Perfect Continuous, Past Perfect Continuous, Future Continuous, or Future Perfect Continuous. BCS sometimes includes trick options using these tenses.
Imperative Sentences
Imperative sentences (commands/requests) follow a special pattern:
| Active |
Passive |
| Open the door. |
Let the door be opened. |
| Do not touch it. |
Let it not be touched. |
| Help me. |
Let me be helped. / You are requested to help me. |
| Please sit down. |
You are requested to sit down. |
Quasi-Passive Sentences
These sentences look active in form but carry a passive meaning. They use intransitive verbs that describe a quality of the subject:
- "The book reads well." (= The book is read well / can be read well)
- "The pen writes smoothly."
- "Rice sells cheap."
- "The door opens easily."
- "Honey tastes sweet."
BCS Trap: If asked "What is the voice?" — these are quasi-passive, not active.
Double Object Sentences
When a sentence has two objects (indirect + direct), either object can become the subject:
- Active: "He gave me (indirect) a book (direct)."
- Passive 1: "I was given a book by him." (indirect object as subject — more common)
- Passive 2: "A book was given to me by him." (direct object as subject)
More examples:
- "The teacher taught us English." → "We were taught English." OR "English was taught to us."
- "She told me a story." → "I was told a story." OR "A story was told to me."
Complex Sentences (BCS Favorite)
Sentences with "People say / think / believe / know / expect":
| Active |
Passive Form 1 |
Passive Form 2 |
| People say that he is honest. |
It is said that he is honest. |
He is said to be honest. |
| People believe that she is rich. |
It is believed that she is rich. |
She is believed to be rich. |
| People know that he was a spy. |
It is known that he was a spy. |
He is known to have been a spy. |
| People expect that he will win. |
It is expected that he will win. |
He is expected to win. |
Sentences That Cannot Be Changed to Passive
- Intransitive verbs (no object): "He sleeps." — No passive possible.
- "Have" meaning possession: "I have a car." — No passive (but "I have done it" → "It has been done by me")
- Reflexive verbs: "He killed himself." — No standard passive.
BCS Shortcuts
- Find the Object first. The object of the active sentence becomes the subject of the passive sentence. No object = no passive.
- Match the tense. Identify the tense of the active verb, then use the corresponding passive structure from the table.
- "By" is optional. If the agent (doer) is obvious or unimportant, "by + agent" can be omitted: "English is spoken worldwide."
- "Let" for imperatives. Command → "Let + object + be + V3".
- "It is said/believed/known" — this pattern covers 80% of complex sentence voice change questions.
Solved Examples (5 BCS-style MCQ)
Q1. Change the voice: "The police arrested the thief."
- (a) The thief is arrested by the police
- (b) The thief was arrested by the police
- (c) The thief has been arrested by the police
- (d) The thief had been arrested by the police
- Answer: (b) The thief was arrested by the police
- Explanation: "arrested" is Simple Past. Passive of Simple Past: was/were + V3. The thief (singular) → "was arrested".
Q2. Change the voice: "Open the door."
- (a) The door is opened
- (b) Let the door opened
- (c) Let the door be opened
- (d) The door should be opened
- Answer: (c) Let the door be opened
- Explanation: Imperative sentences in passive voice use the structure: Let + object + be + V3.
Q3. "The book reads well" — this sentence is an example of:
- (a) Active voice (b) Passive voice (c) Quasi-passive (d) None of these
- Answer: (c) Quasi-passive
- Explanation: The subject "book" is not performing the action of reading. It is being read. But the sentence is structured like active voice. This is quasi-passive.
Q4. Change the voice: "People believe that he is innocent."
- (a) It is believed that he is innocent
- (b) He is believed that he is innocent
- (c) That he is innocent is believed
- (d) He was believed to be innocent
- Answer: (a) It is believed that he is innocent
- Explanation: "People + verb + that clause" → "It is + V3 + that clause." Alternative: "He is believed to be innocent." Option (a) matches the standard transformation.
Q5. He gave me a pen. (Passive voice)
- (a) A pen was given me by him
- (b) I was given a pen by him
- (c) A pen is given to me by him
- (d) I am given a pen by him
- Answer: (b) I was given a pen by him
- Explanation: Double object sentence. "Gave" is Simple Past. Either object can become the subject, but making the indirect object (me → I) the subject is more natural: "I was given a pen by him."
Common Mistakes — Watch Out!
- Quasi-passive confusion: "Rice sells cheap" LOOKS active but has passive meaning. Do not try to convert it — it is already quasi-passive.
- Tense mismatch: "He wrote" (past) → must become "was written" (past), not "is written" (present). Always match the tense.
- "Let" structure errors: It is "Let the door be opened" — not "Let the door opened" (missing "be").
- No passive for intransitive verbs: "He laughed" has no object, so it cannot be made passive. If a BCS question asks you to change such a sentence, look for the option that says "No passive possible."
- Continuous passive limits: There is no passive for Perfect Continuous tenses. If you see "has been being written" — it is wrong.
Question Pattern Recognition
Pattern 1 — "Change the voice":
Step 1: Find the object → make it the subject. Step 2: Match the tense. Step 3: Add "by + original subject" if needed.
Pattern 2 — "Identify the voice":
Look for "be + V3" (passive) or a quasi-passive structure. If neither is present and the subject is doing the action, it is active.
Pattern 3 — "People say/believe/know":
Two standard conversions: "It is said that..." or "He is said to be..." — one of these will always be the answer.
Pattern 4 — Imperative voice change:
If the original sentence is a command (no subject visible), the passive uses "Let + object + be + V3."
Pattern 5 — Double object:
Check which object is made the subject. The indirect object (person) becoming the subject is the more common BCS answer.