OET Writing Mistakes That Cost You a Grade B

The OET Writing sub-test has always been demanding. Many candidates land on Grade C+ or even Grade C, often because of mistakes they do not realise they are making. After marking thousands of letters, I see the same ten patterns again and again. This article walks through each one, with a short example, the marking reason, and a practical fix.

Why these mistakes cost the grade

Before the mistakes, a quick note on where marks are lost. The six OET Writing criteria and their descriptors have been unchanged since August 2018, and OET has announced no change to marking. In the letters we correct, the questions that decide most grades are whether the letter identifies the right purpose, whether the clinical detail it includes is what the recipient actually needs, and whether Genre and Style stays consistent rather than drifting between formal referral language and casual handover language. If your score dropped without your writing dropping, check these first. For a fuller breakdown, see our OET writing criteria for Grade B guide.

Mistake 1: Burying the Purpose in paragraph two

The Purpose criterion expects the reader to understand why the letter is being written and what is being requested within the first two or three sentences. Many candidates open with a long sentence about the patient’s background and only state the request in paragraph two.

Example, weak opening: “Mrs Khan is a 67-year-old patient who has been under my care for the past three weeks following a fall at home, during which she sustained a fractured neck of femur, and who has now reached the point at which she can be safely discharged into the community.”

The reader has read 45 words and still does not know what is being asked. The fix is to lead with the request and then provide the background.

Better: “I am writing to refer Mrs Khan, a 67-year-old patient recovering from a fractured neck of femur, for ongoing community physiotherapy following discharge.”

The same information, but the Purpose is now visible at sentence one.

Mistake 2: Treating every case note as equally important

The Content criterion rewards clinical relevance. Candidates often copy across detail that the recipient does not need, while leaving out detail that the recipient does need. A community pharmacist receiving a referral does not need the full history of the fall; they need the current medication, the allergies, and the dispensing schedule. A specialist receiving a referral does need the relevant history, but only the relevant history.

The fix is to ask, before you write, who is the recipient and what do they need to know. Our common mistakes guide covers this filter in more detail.

Mistake 3: Copy-paste from case notes

Lifting whole phrases from the case notes is one of the fastest ways to lose Conciseness and Clarity marks. The case notes are written in shorthand, with abbreviations and fragments. The letter must be written in full sentences, with controlled register. Copying directly produces sentences that read like dictation, not communication.

The fix is to paraphrase every line. If a case note says “pt c/o SOB on exertion x 3/52,” the letter version is “Mrs Khan has reported shortness of breath on exertion for the past three weeks.”

Mistake 4: Inconsistent register

Genre and Style marks drop when a letter shifts between formal referral language and informal handover language. Sentences like “Please could you kindly possibly arrange to see Mrs Khan if you would” sit awkwardly next to “She has been fine since.” The reader experiences this as inconsistency.

Pick a register and hold it. For most OET letters, the register is formal, professional, and measured. Our tone and register guide gives example sentences at each level.

Mistake 5: Grammar errors that change meaning

Not all grammar errors carry equal weight. An error that does not change meaning, like “Mrs Khan have been recovering well,” is a small deduction. An error that changes meaning, like “Mrs Khan was prescribed warfarin since two days,” can suggest to the examiner that the writer is not in control. Patterned errors, the same mistake repeated four or five times in the letter, also push the Language band down quickly.

The fix is targeted, not general. Identify your patterned errors and drill them. Our grammar problems guide lists the ten patterns I see most often in healthcare writers.

Mistake 6: Weak cohesion between paragraphs

Cohesion marks drop when paragraphs read like a list of facts rather than a narrative. The reader should feel pulled from one paragraph to the next. Linking phrases like “In addition,” “However,” and “Since then” do this work, but they have to be used purposefully, not sprinkled at the start of every sentence.

The fix is to plan your paragraph order before you write, and to use linking phrases only where the relationship between paragraphs needs to be signposted. Our cohesion guide has a paragraph-planning template.

Mistake 7: Forgetting the closing request

Many letters trail off into pleasantries without restating the request. The reader is left wondering exactly what is being asked. A strong closing restates the request in clear professional language and offers a contact route.

Weak: “Thank you for your time. I look forward to hearing from you soon.”

Better: “I would be grateful if you could arrange a follow-up appointment within the next two weeks. Please do not hesitate to contact me on extension 4421 if you require any further information.”

Mistake 8: Word count drift

The OET Writing word count window is approximately 180 to 200 words. Letters that creep to 250 lose Conciseness marks. Letters that come in under 160 lose Content marks. Many candidates lose track of word count under pressure and only realise at the end. Practise writing to 190 words consistently, so that 190 words feels natural rather than calculated.

Mistake 9: Using formal templates without adapting them

Memorised templates feel safe, but they are easy for an experienced marker to spot. A letter that opens “I am writing to refer the above-named patient” before naming the patient sounds like a template. A letter that opens “I am writing to refer Mrs Khan, a 67-year-old patient” sounds like communication. The fix is to use phrase banks, not full templates. Internalise the openings and closings, but always tailor the middle to the case.

Mistake 10: Submitting without rereading

The single highest-yield five minutes in the OET Writing exam is the final reread. Most candidates skip this because they have just finished writing and feel time pressure. Yet the reread is where you catch the verb tense slip, the missing article, the paragraph that drifted from the Purpose. Plan to finish writing five minutes before the end of the test. Use those minutes to read the letter back as if you were the recipient.

The pattern across all ten

The common thread across these ten mistakes is that they are all visible to the writer once they are pointed out, but invisible to the writer while they are writing. This is why expert educator correction matters. A writer cannot easily see their own patterned errors. A trained marker can. For deeper structural coverage, see our what examiners look for in OET letters guide.

Side-by-side: a letter before and after correction

The Grade B version is not longer. It is shorter, but more precise. Precision is what the criteria reward.

What to do next

If you are stuck at Grade C+ and aiming for Grade B, the fastest route forward is to write, get corrected by a marker, and rewrite. Most candidates need between 8 and 15 corrected letters, not just written letters, to move up a band. Our expert educator correction at OET writing services is designed exactly for this loop. You can also start with our free Writing Checker to get a baseline reading of where your letters currently sit, then move to expert educator correction for the targeted work that closes the gap.

The mistakes above are common because they are subtle. None of them feel like big errors while you are writing. They only become visible when somebody else reads the letter. That is the work to do.