Apostrophes and Possessives in OET Writing: The Patient's History, Not Patients History

“Please review the patients history and advise on further management.” One missing apostrophe, and the sentence no longer tells the reader whether you mean one patient or several. Apostrophes and possessives are a small, mechanical part of OET writing, but they carry real information — who owns what, how many people are involved — and getting them wrong is one of the most common Language-criterion errors examiners see precisely because the error looks trivial while the ambiguity it creates is not.

Why do apostrophes matter for your OET Writing band?

The OET Writing sub-test is marked against six official criteria set by CBLA, the OET’s governing body: Purpose, Content, Conciseness & Clarity, Genre & Style, Organisation & Layout, and Language. Apostrophe use sits inside Language, which assesses the accuracy and range of grammar, spelling, and mechanics across the entire letter.

An apostrophe error rarely sinks a letter on its own. The real problem is twofold. First, apostrophe mistakes in clinical writing are not purely cosmetic — “the patients history” genuinely leaves the reader unsure whether one patient or several are being discussed, which is a Content and Clarity issue dressed up as a punctuation slip. Second, like most mechanical errors, apostrophe mistakes rarely appear once. A candidate who drops the apostrophe in one possessive tends to drop it everywhere, because the error comes from an unlearned rule rather than a one-off typo, and examiners are trained to read that repeated pattern as reduced control over written mechanics. The good news is that the rules below cover a small, closed set of patterns — there are no real exceptions once you know which of the three jobs an apostrophe is doing in a given word.

How do you form a possessive with a patient’s name?

The core rule is simple: add ’s to a singular noun to show it owns something. “The patient’s history” means the history belonging to one patient. “The consultant’s recommendation” means the recommendation made by one consultant. “Mrs Ahmed’s blood pressure” means the blood pressure reading belonging to Mrs Ahmed.

This holds for every singular noun in a referral or discharge letter, whether it names a person, a role, or an object:

• the patient’s discharge date
• the GP’s instructions
• the ward’s protocol
• the wound’s appearance

The test is always the same: if you can rephrase the phrase as “the X belonging to Y” or “the X of Y,” the possessive apostrophe is correct. “The patient’s history” rephrases cleanly as “the history of the patient” — so the apostrophe belongs there.

What happens when a name already ends in -s?

This is where OET candidates most often hesitate, because general English teaching sometimes allows two different conventions. For a singular name that already ends in -s — Mr Jones, Ms Phillips, Dr Collins — the OET-appropriate convention is still to add ’s, producing “Mr Jones’s discharge letter,” “Ms Phillips’s observations,” “Dr Collins’s referral.”

Some style guides permit dropping the extra s for names ending in -s (writing “Jones’” instead of “Jones’s”), and you may see this in general British usage. In a clinical letter, however, the fuller “Jones’s” form is the safer choice: it is unambiguous, it matches the pattern every other possessive in the letter follows, and it avoids the small but real risk that “Jones’” reads as a typo for the plural “Joneses.” Pick the “add ’s always” rule and apply it consistently, and you remove this decision from every sentence in the letter at once.

How do you punctuate plural possessives?

Plural possessives follow a different pattern, and mixing the two up is the single most consequential apostrophe error in clinical writing, because it changes how many people a sentence is about.

If the plural noun already ends in -s (which almost all regular English plurals do), add only an apostrophe after the existing s — no extra s is added:

• the patients’ records (the records belonging to several patients)
• the nurses’ handover notes (the notes belonging to several nurses)
• the doctors’ recommendations (the recommendations made by several doctors)

If the plural noun is irregular and does not end in -s (children, women, men, staff), the rule reverts to the singular pattern — add ’s:

• the children’s vaccination schedule
• the women’s health clinic
• the staff’s rota

That last row is worth pausing on, because it is a different error from the first two: it is an apostrophe inserted where none is needed at all. “The patient’s were seen today” has no possession in it whatsoever — “patients” is simply plural, so no apostrophe belongs anywhere near it. This is the single most common apostrophe mistake in OET letters: treating the letter -s on the end of a plural as if it always needs an apostrophe in front of it. It never does, unless that same word is also showing ownership.

Its or it’s — which one belongs in a referral letter?

“Its” and “it’s” are two different words that happen to sound identical, and the rule is fixed rather than contextual.

“Its” (no apostrophe) is the possessive form of “it.” “The wound and its edges were inspected” means the edges belonging to the wound. “The medication and its side effects were explained to the patient” means the side effects belonging to the medication.

“It’s” (with an apostrophe) is a contraction of “it is” or “it has” — “it’s been three weeks since the surgery,” “it’s important to monitor the dressing.” Contractions are generally avoided in formal OET register regardless of whether they are used correctly, which means a letter written in appropriately formal style should almost never need the word “it’s” at all. If you find yourself about to type “it’s,” check first whether you actually mean the possessive “its,” and if you do mean the contraction, expand it to “it is” or “it has” instead.

Do eponymous conditions keep their apostrophe?

Yes, and this is the one place where the possessive apostrophe survives even though no literal ownership is intended. Conditions named after the person who first identified or described them — Parkinson’s disease, Crohn’s disease, Alzheimer’s disease, Graves’ disease — keep the apostrophe as a fixed part of the spelling. The apostrophe here is historical rather than grammatical: it marks that the disease is “Parkinson’s” in the sense of being associated with Dr James Parkinson, not that Parkinson currently owns anything. Our capitalization guide covers the related rule for these same terms — the proper noun keeps its capital letter, while “disease” and “syndrome” stay lowercase.

Note the exception within the exception: Graves’ disease is conventionally written with a bare apostrophe, not “Graves’s,” because the possessive form was fixed in medical usage before the “always add ’s” convention became standard for patient names in letters. Where a condition name is this well-established, use the spelling you see in clinical references rather than applying the general rule mechanically.

A 60-second apostrophe self-check before you submit

Apostrophe errors are mechanical, which means they are fast to check for once you know exactly what to look for. Run this pass as a dedicated final read:

1. Find every apostrophe in the letter. For each one, ask: is this showing possession, or forming a contraction? If it’s neither, delete it.
2. Find every plural noun ending in -s that has no apostrophe. Confirm none of them should be possessive — if “the patients records” appears without an apostrophe, decide whether you mean one patient’s records or several patients’ records, and add the apostrophe in the right place.
3. Check every name ending in -s. Confirm you’ve used the fuller “‘s” form consistently — “Jones’s,” not “Jones’.”
4. Search for “it’s.” If it appears, check whether you meant the possessive “its” instead, and whether the sentence should be rephrased to avoid the contraction altogether.

Our grammar tips guide covers the eight most frequent Language-criterion errors more broadly, and our punctuation guide walks through the mechanics errors examiners flag most often alongside apostrophes. If list punctuation is also tripping you up, our Oxford comma guide covers the house rule for listing symptoms and medications without ambiguity. For the full band-by-band breakdown of how Language is scored, see our Language criterion guide.

Where self-editing hits its limit

Apostrophe errors are genuinely hard to catch by re-reading your own letter, because your eye tends to read the word you meant rather than the punctuation actually sitting on the page — “the patients history” and “the patient’s history” look almost identical at a glance, even though they tell the reader different things.

The free Grammar Checker is a solid first pass for catching some of these mechanically, but a full read against all six criteria — checking apostrophe accuracy alongside content, structure, and register together — is what actually confirms a letter is ready to submit. Our OET writing correction service has reviewed more than 11,000 letters since 2014 against the exact criteria examiners use, catching mechanical slips like misplaced apostrophes before they cost you Language marks. If you’re comparing options before booking, our pricing page breaks down turnaround and pack sizes from a single letter up to full exam preparation.