Passive Voice in OET Writing: When It Helps and When It Hides the Subject

Passive voice in OET writing is not an error to eliminate — it’s a register choice examiners expect you to make correctly, and most candidates get the decision backwards. Some over-correct into rigid active-voice sentences that sound blunt for clinical register. Others hide behind passive constructions in exactly the sentences where the reader needs to know who did what. Both mistakes cost marks, but they cost different marks, under different criteria, and the fix for one is not the fix for the other.

Watch the full breakdown: Passive Voice in OET works through the same decision using real referral and discharge letter sentences.

Why does OET writing use so much passive voice in the first place?

Medical and clinical correspondence has used passive voice as its default register for procedures, findings, and interventions for longer than OET has existed as an exam. When a discharge summary says “the patient was commenced on antibiotics” rather than “Dr Osei commenced the patient on antibiotics,” it isn’t dodging responsibility — it’s following a convention where the clinical fact (antibiotics were started) outranks the administrative detail (who specifically wrote the prescription) for the letter’s purpose.

This convention exists because most clinical writing describes processes and outcomes that belong to a team, a ward, or an institution rather than to one identifiable individual, and because the reader of a referral or discharge letter is almost always another clinician who cares about the clinical picture, not the staffing roster. “Observations were recorded hourly” tells a receiving nurse everything they need. Naming which specific nurse recorded them adds nothing and would actually read as an odd, over-specific detail in that register.

OET writing inherits this convention directly, which is why letters written entirely in active voice — “I gave the patient medication,” “I checked the wound,” “I recorded the observations” — often read as less professional to an examiner, not more, despite being grammatically flawless. The Genre and Style criterion rewards writing that matches the conventions of real clinical correspondence, and real clinical correspondence leans passive for exactly this class of routine action.

When is passive voice the correct choice in an OET letter?

Passive voice is the right choice whenever the reader can act correctly on the sentence without knowing who specifically performed the action. Three situations come up constantly in OET case notes:

Routine clinical procedures and monitoring. “Blood pressure was monitored four-hourly.” “The dressing was changed on alternate days.” “A full blood count was requested on admission.” In every case, the procedure and its result matter to the receiving clinician; the identity of whoever carried it out does not.

Findings and results, where the finding is the point. “No abnormality was detected on chest X-ray.” “Raised inflammatory markers were noted on the blood panel.” The result is the clinically relevant fact. Restructuring these into active voice — “The radiologist detected no abnormality” — adds a subject nobody asked about and pushes the actual finding further from the front of the sentence.

Actions where the patient is the logical subject and the agent is institutionally obvious. “The patient was admitted to the medical ward.” “She was discharged on the fourth post-operative day.” Naming “the hospital admitted the patient” is unnecessary; the fact of admission and its timing are what matters.

In all three cases, using active voice instead isn’t a grammar error — it’s a register mismatch. It makes the letter read like a personal account rather than a clinical document, and that mismatch is scored under Genre and Style even when every sentence is otherwise correct.

When does passive voice hide information the reader needs?

The failure mode is different, and it’s more serious, because it isn’t a style issue — it’s a missing fact. Passive voice becomes an error the moment it removes a subject the reader actually needs in order to know what to do next.

Compare these two sentences from a referral letter:

“Further investigation was recommended.”

“I have referred Mr Tan for further cardiology investigation.”

The first sentence tells a receiving cardiologist that investigation was recommended — by whom is unclear. Recommended by the writer, sending this letter as the referral itself? Recommended by someone else already, meaning this letter is a follow-up rather than the referral itself? The passive construction has erased exactly the information the reader needs to know what action, if any, they’re expected to take. That is a Content-criterion problem: a required piece of information is simply absent from the letter, not just phrased less elegantly.

The same failure shows up around prescribing and decision-making generally. “Medication was prescribed” doesn’t tell a GP whether the hospital started a new medication that needs monitoring, whether the GP’s own existing prescription was continued, or whether a specialist changed a dose. “The consultant increased the metformin dose to 1g twice daily” removes all of that ambiguity in one sentence, because it names both the agent and the specific action.

The test: does the missing subject create real ambiguity?

Run this test on every passive sentence before you submit, because it separates the two situations above cleanly:

Could a reader act correctly on this sentence without knowing who performed the action?

• If yes — the action is routine, the result is what matters, or the agent is institutionally obvious — passive voice is the better clinical choice. Leave it.
• If no — the reader needs to know whether it was you, a specialist, the patient themselves, or someone else, in order to know what to do next — switch to active voice and name the agent.

This test works because it targets the actual reason passive voice costs marks: not the grammatical construction itself, but the information gap it can create. A discharge letter with ten passive sentences describing routine ward care is following clinical convention correctly. A referral letter with one passive sentence hiding who is responsible for the next clinical decision has a genuine content problem, regardless of how many other sentences in the letter are perfectly formed.

Worked examples: fixing the sentences that need fixing

Notice that every fix does the same thing: it restores an agent (usually “I,” since most OET writing tasks are written in the first person as the referring or treating clinician) exactly where the reader would otherwise have to guess.

A quick self-check for your next letter

Read through your draft and mark every passive-voice sentence. For each one, ask only the test question above — does the reader need the missing subject? Most of your passive sentences will pass the test immediately, because most clinical detail genuinely doesn’t need an agent attached. The ones that fail are almost always clustered around recommendations, referrals, and prescribing decisions — exactly the sentences where the letter’s whole purpose depends on the reader knowing what action has or hasn’t been taken, and by whom.

This check pairs well with a broader grammar pass — our 8 grammar errors guide covers the other Language-criterion errors that tend to appear in the same letters, and the Content criterion breakdown explains exactly what counts as a missing information gap versus a stylistic weakness. If you want to check whether your own passive constructions are hiding a required subject, our free OET Grammar Checker is a useful first pass, though it won’t catch every context-dependent ambiguity a human reader will.

The honest limit of self-editing here

Passive voice is one of the hardest issues to self-edit, because both failure modes — over-using active voice and hiding a subject in passive voice — sound completely natural to the person who wrote them. You know who you mean by “was referred.” Your reader doesn’t. That gap is invisible from the inside, which is exactly why it survives so many rounds of proofreading intact. Our OET writing correction service reviews your letters against all six criteria, including exactly this kind of Content-level ambiguity that a spelling-and-grammar pass alone won’t surface.