Passive voice
The passive reorganizes a clause so that the affected participant becomes subject and the agent can be omitted or backgrounded.
01 · Concept foundation
Understand the terms before applying the rule
Each term below names a different grammatical object. Open examples and compare their function rather than memorising a Vietnamese translation alone.
passive voice/ˈpæsɪv vɔɪs/
thể bị độngThe be/get + past participle construction presenting the subject as affected by an action.
The model was calibrated.
Mô hình được hiệu chỉnh.
agent/ˈeɪdʒənt/
tác nhânThe participant responsible for carrying out an action.
by the research team
bởi nhóm nghiên cứu
patient/ˈpeɪʃənt/
đối thểThe participant affected or changed by an action.
the model in The model was calibrated
the model trong The model was calibrated
Complete lesson scope
Do not stop at one formula
Passive across simple, progressive, perfect and modal forms
Agent omission, by-phrases and information structure
Get-passive and causative have/get something done
Reporting passives and impersonal constructions
Decision boundary: Use passive voice to manage viewpoint and information flow, not simply to make prose sound formal.
02 · Controlling rule
The passive reorganises information rather than merely replacing an active sentence. The affected participant becomes subject, the auxiliary be carries tense and aspect, and the lexical verb appears as a past participle. A by-agent is added only when it identifies a relevant source of action or responsibility. Spoken English often prefers an active clause or a get-passive for personal events; academic and technical writing often prefers a be-passive when procedure, result or evidence is the topic.
patient + finite be + V3 (+ by agent) | modal + be + V3 | have + been + V3 | be + being + V3 | have/get + object + V3Passive voice as information structure, not decoration
Choose active, be-passive, get-passive, causative and reporting passive structures according to agency, information focus, register and communicative purpose.
Voice answers a discourse question: should the clause begin with the agent, the affected participant, the process or the result?
The passive does not merely reverse word order. It preserves tense/aspect in be, changes the lexical verb to a past participle, promotes the object to subject position and re-organises given/new information. Overusing it can hide responsibility; underusing it can make methods and results unnecessarily agent-centred.
Is the agent known, relevant and worth foregrounding?
Does the verb take an object and therefore allow an ordinary passive?
Which tense, aspect and modality must be preserved in the auxiliary chain?
Is be-passive, get-passive, a causative or a reporting construction the most natural choice?
1. Core formation across tense and aspect
The passive keeps the original time/aspect meaning in the auxiliary chain and changes only the lexical verb to a past participle.
subject + finite be + past participle (+ by-agent)Present simple: is/are + V3; past simple: was/were + V3; present perfect: has/have been + V3.
Progressive passive uses being: is being measured; perfect progressive passive is possible but often stylistically heavy.
Modal passive uses modal + be + V3; perfect modal passive uses modal + have been + V3.
Only transitive uses of verbs ordinarily form a passive; an intransitive verb such as arrive has no object to promote.
The water level is recorded every ten minutes.
The water level is recorded every ten minutes.
Present simple passive describes a regular procedure.
The boundary condition has been revised after the sensitivity analysis.
The boundary condition has been revised after the sensitivity analysis.
Present perfect passive foregrounds the current result of a completed revision.
Be-passive
subject + be (tense/aspect) + V3 (+ by-agent)Foreground process, result or affected participant.
is measured
was calibrated
has been validated
will be reviewed
- Keep agreement and tense in be; use the past participle for the lexical verb.
Get-passive
subject + get + V3Present an event or change affecting the subject, especially in speech.
got injured
gets damaged
got promoted
- Avoid it in very formal methods prose unless the eventive nuance is intended.
Causative service pattern
have/get + object + V3Arrange for another person to do the action, or report an adverse event from context.
We had the sensor repaired.
She got her phone stolen.
- The object receives the action; it does not perform it.
Reporting passive
It is said that... · X is said to... · X is believed to have...Attribute a proposition impersonally or synthesise a general position.
It is widely accepted that...
The process is believed to be reversible.
- Name the source when source identity matters.
Agent focus versus process focus
The research team calibrated the model.
The team and its responsibility are foregrounded.
The model was calibrated using two events.
The model and method are foregrounded.
Choose the subject that best continues the paragraph topic and preserves necessary responsibility.
Be-passive versus get-passive
The device was damaged during transport.
Neutral report of state/event.
The device got damaged during transport.
More conversational and eventful; often suggests an unwanted outcome.
Use be for neutral/formal reporting and get when the affected-event nuance matters.
Agent by versus instrument with
The samples were analysed by the laboratory team.
The phrase names the agent.
The samples were analysed with a laser scanner.
The phrase names the instrument.
Use by for who/what performs the action; use with for the instrument or material.
Everyday conversation and IELTS Speaking
- Prefer
- Use active clauses for clear personal agency and get-passives for natural descriptions of events affecting people.
- Avoid
- Long impersonal passive chains that sound memorised.
- Why
- Speaking needs transparent agency and manageable processing.
IELTS Task 1 processes and academic methods
- Prefer
- Use be-passives when stages, materials and outputs are the topic: is heated, is transferred, was analysed.
- Avoid
- Adding by people/by workers when the agent is obvious and irrelevant.
- Why
- Process descriptions foreground sequence and transformation rather than routine human agency.
Critical and policy writing
- Prefer
- Use active voice when assigning responsibility; use passive only when the affected outcome is genuinely the discourse topic.
- Avoid
- Agentless wording that obscures who made a decision or caused harm.
- Why
- Voice choice changes accountability, not only style.
Do not translate markers mechanically: reconstruct the relation and viewpoint
Markers of affectedness
Passive voice is grammatical structure: be/get + past participle, with tense and agreement in the auxiliary.
Bị and được often add negative/positive affectedness, but Vietnamese can express passive-like meaning without either marker.
Do not translate every bị/được mechanically, and do not add by-agent unless English discourse needs it.
Topic continuity
Subject position strongly organises paragraph information flow.
Topic-comment organisation can remain clear without the same morphological passive marking.
When translating, rebuild the English clause around the intended paragraph topic rather than copying surface order.
Passive tense-aspect matrix
Preserve the intended time/aspect in the auxiliary chain.
| Meaning | Pattern | Example |
|---|---|---|
| present routine | am/is/are + V3 | is recorded |
| past event | was/were + V3 | was installed |
| current result | has/have been + V3 | has been revised |
| ongoing process | is/are being + V3 | is being tested |
| modal requirement | modal + be + V3 | must be checked |
Voice and construction choice
Choose by function and register, not by a belief that passive is always more academic.
| Purpose | Preferred form | Typical context |
|---|---|---|
| assign responsibility | active | policy critique |
| describe procedure | be-passive | methods / Task 1 |
| affected event | get-passive | conversation |
| arranged service | have/get O V3 | daily life |
✕ The data were collect in March.
✓ The data were collected in March.
Passive voice requires a past participle after be.
✕ The samples analysed yesterday.
✓ The samples were analysed yesterday.
A finite passive needs a finite form of be unless the clause is deliberately reduced.
✕ The valve must checked before use.
✓ The valve must be checked before use.
Modal passive uses modal + be + past participle.
✕ We had repaired the sensor by a technician.
✓ We had the sensor repaired by a technician.
The service causative places the receiving object before the past participle.
Choose by relation, viewpoint and discourse role
1. Which passive preserves present perfect meaning?
2. Which sentence is most natural in a methods section?
3. Which sentence naturally describes an adverse conversational event?
4. Which construction means that another person repaired the sensor for us?
Write one natural Speaking sentence with a get-passive and a four-sentence methods paragraph using be-passives only where process or result is the real topic. Underline every auxiliary chain.
Tense and aspect are preserved in the auxiliary chain.
The past participle is correct, including irregular forms.
The agent is omitted or included for a clear reason.
Voice choice supports information flow and accountability.
03 · Worked examples
Observe form, function and meaning together
The model was calibrated against two independent events.
Mô hình được hiệu chỉnh theo hai sự kiện độc lập.
The boundary conditions have been revised since the sensitivity analysis.
Các điều kiện biên đã được điều chỉnh kể từ phân tích độ nhạy.
The samples are being analysed in the coastal laboratory.
Các mẫu đang được phân tích trong phòng thí nghiệm ven biển.
The uncertainty should be reported explicitly.
Độ bất định nên được báo cáo rõ ràng.
The team had the sensor repaired before deployment.
Nhóm đã cho sửa cảm biến trước khi triển khai.
Two gauges got damaged during the storm.
Hai máy đo đã bị hư hại trong cơn bão.
04 · High-risk contrast
Explain why one form fails, not only which answer is correct
The data were collect in March.
The data were collected in March.
The finite auxiliary were carries past tense and plural agreement; the lexical verb must be the past participle collected. A base form after be does not construct a passive.
05 · Mastery check
Apply the rule before marking the lesson complete
Which sentence is grammatically acceptable in the target system?
Which description best defines “passive voice”?
Which example is one of the verified target patterns in this lesson?
Which structural formula belongs to this lesson?
Complete all four checks, then submit a sentence for target-form feedback.
06 · IELTS Academic
Transfer grammar into a real communicative task
Use the passive in Task 1 process descriptions, research methods and technical reports when the operation or result matters more than the operator. In Task 2, combine active and passive clauses so responsibility is not hidden. In Speaking, active clauses are usually more direct, while the passive is useful for places, traditions, services and personal experiences such as I was given or I got invited.
Form simple, perfect, progressive, modal and causative passives with correct participles.
Explain why an active, be-passive or get-passive is preferable in a specific context.
Distinguish by-agent, with-instrument and agentless passive functions.
Use the passive without obscuring evidence, responsibility or causal reasoning.