8.1 Active & Passive Voice
Key Takeaways
- In passive voice, the object of the active sentence becomes the subject and the verb becomes a form of be plus the past participle (V3).
- Each tense has a fixed passive formula: simple present uses is/am/are + V3, simple past uses was/were + V3, present perfect uses has/have been + V3.
- Only transitive verbs (verbs that take a direct object) can be passivized; intransitive verbs like sleep, arrive, and die have no passive form.
- Modals become modal + be + V3 (can fly -> can be flown), and the agent is introduced with by only when it carries new information.
8.1 Active & Passive Voice
Quick Answer: In passive voice, the object of the active sentence becomes the subject, and the main verb becomes be + past participle (V3). The original doer moves into a by-phrase that can be dropped when it is obvious or unimportant.
Voice describes the relationship between the verb's action and its subject. In the active voice, the subject performs the action: The pilot flies the aircraft. In the passive voice, the subject receives the action: The aircraft is flown by the pilot. The PAF English paper typically asks you to choose the correct passive of a given active sentence, or to spot a voice shift that breaks parallelism.
The Transformation Recipe
- Object of the active verb becomes the subject of the passive.
- Main verb becomes the matching form of be + past participle (V3).
- Subject of the active verb becomes the agent in a by-phrase, which is optional.
Tense-by-Tense Transformation Table
| Tense | Active Form | Passive Form | Example (Active -> Passive) |
|---|---|---|---|
| Simple present | fly / flies | is / am / are + V3 | The cadet flies the jet -> The jet is flown by the cadet. |
| Present continuous | is / am / are + V-ing | is / am / are + being + V3 | The crew is inspecting the engine -> The engine is being inspected by the crew. |
| Simple past | flew | was / were + V3 | The base launched the sortie -> The sortie was launched by the base. |
| Past continuous | was / were + V-ing | was / were + being + V3 | They were testing the radar -> The radar was being tested by them. |
| Present perfect | has / have + V3 | has / have + been + V3 | The tower has cleared the runway -> The runway has been cleared by the tower. |
| Past perfect | had + V3 | had + been + V3 | The crew had repaired the wing -> The wing had been repaired by the crew. |
| Simple future | will + V1 | will + be + V3 | The academy will publish the results -> The results will be published by the academy. |
| Modals (can, must, should) | modal + V1 | modal + be + V3 | Cadets must wear the uniform -> The uniform must be worn by cadets. |
Worked Examples
Example 1 (simple present): The instructor briefs the trainees. -> The trainees are briefed by the instructor. The object the trainees (plural) becomes the subject, so the auxiliary is are, and briefs becomes briefed.
Example 2 (present perfect): The maintenance team has serviced the helicopter. -> The helicopter has been serviced by the maintenance team. Note the has been + V3 pattern; has serviced becomes has been serviced.
Example 3 (modal): Candidates must pass the medical. -> The medical must be passed by candidates. The modal must stays, pass becomes be passed.
Common Traps
- Intransitive verbs have no passive. Verbs like sleep, arrive, die, happen, occur take no object, so they cannot be passivized. The cadet slept has no passive form.
- Retained object. Some verbs take two objects (give, send, offer). Either object can become the passive subject: The officer gave the cadet a task -> A task was given to the cadet OR The cadet was given a task. The second still contains an object (a task), called the retained object.
- Don't change the tense. A frequent MCQ trap keeps the tense right but flips the verb form wrong: The jet was flown (simple past passive) is correct; The jet is being flown (present continuous passive) is wrong if the original was simple past.
- By-phrase is optional, not forbidden. Drop it only when the doer is obvious, unknown, or unimportant. Keep it when it adds real information.
Voice and Parallelism
When two clauses share a subject, keep the same voice in both. Mixed voice is a classic error: The plane took off and the runway was cleared is awkward; The plane took off and the tower cleared the runway keeps both clauses active.
More Worked Transformations
Example 4 (future perfect): By 2027, the academy will have trained thousands of pilots. -> By 2027, thousands of pilots will have been trained by the academy. The future perfect active is will have + V3; the passive is will have been + V3. Note that been sits between have and the past participle, and the by-phrase is kept because it carries real information.
Example 5 (modal perfect): The engineer should have serviced the rotor. -> The rotor should have been serviced by the engineer. Modal-perfect passives follow modal + have been + V3. A common MCQ trap inserts the base verb instead of the participle: should have been service is wrong; the V3 serviced is required.
Example 6 (question form): Did the crew inspect the landing gear? -> Was the landing gear inspected by the crew? When the active sentence is a question, the passive question opens with the matching be-form (was), then the new subject (the landing gear), then V3, then the by-phrase. Do not carry the auxiliary did into the passive.
Trap: Intransitive Verbs Have No Passive (Revisited)
This is the most-tested trap in the voice set, so it deserves a second look. The squadron arrived at 0600 cannot become 0600 was arrived by the squadron — arrive takes no object, so there is nothing to promote to subject. Other common intransitives on the PAF list: sleep, happen, occur, die, exist, fall (intransitive sense). If an MCQ option forces any of these into a passive frame, eliminate it immediately — the test writer is checking whether you notice that the verb has no object to front.
Quick Decision Flow
- Identify the tense of the active verb.
- Write the be-form that matches that tense and the new subject's number.
- Add the past participle (V3) of the main verb.
- Add by + agent if the doer is meaningful.
- Check that no intransitive verb has been forced into passive.
Choose the correct passive of: 'The tower has cleared the runway for landing.'
Which sentence can be correctly converted into the passive voice?
Convert to passive: 'Cadets must wear the uniform during parade.'
Identify the error in this passive: 'The engine was being inspect by the technician when the alarm sounded.'