15 Common IELTS Writing Mistakes That Lower Your Band

Why small mistakes cost you more than you think

IELTS Writing is marked against four equally weighted criteria: Task Achievement/Response, Coherence and Cohesion, Lexical Resource, and Grammatical Range and Accuracy. A single weak criterion pulls your overall band down, even if the other three are strong.

Most candidates lose marks not because they lack ideas, but because of recurring habits — the same handful of errors appear essay after essay. The good news is that once you can spot these patterns, they're straightforward to correct.

Below are 15 of the most common mistakes, grouped by criterion, each with a practical fix you can apply in your next practice essay.

Task Response mistakes

These errors affect Task Achievement (Task 1) and Task Response (Task 2) — the criterion examiners check first, because a beautifully written essay that doesn't answer the question is capped at band 5.

• Mistake 1 — Answering a memorised or half-related question instead of the one asked. Fix: underline every part of the prompt before you plan. If it asks for 'advantages and disadvantages', write both — not just your opinion.
• Mistake 2 — Writing a one-sided essay when the question asks you to discuss both views. Fix: give a genuine paragraph to each side, then state your own view clearly, usually in the conclusion.
• Mistake 3 — Only partially addressing multi-part questions (e.g. discussing causes but forgetting solutions). Fix: turn the prompt into a checklist and tick off each part in your plan before writing.
• Mistake 4 — In Task 1, listing every single data point instead of identifying an overview and key trends. Fix: always write a clear overview paragraph naming the two or three most significant features before your detail paragraphs.

Coherence and Cohesion mistakes

This criterion rewards logical organisation and natural linking — not the number of connectors you use. Overdoing cohesion devices is almost as damaging as ignoring them.

• Mistake 5 — Overusing linking words mechanically ('Firstly... Secondly... Moreover... In addition...' in every paragraph). Fix: use a mix of linking words, pronoun reference, and simple repetition of key ideas so the writing flows naturally rather than sounding like a checklist.
• Mistake 6 — Paragraphs with no clear central idea, jumping between points. Fix: start each body paragraph with a topic sentence that states its one main idea, then support it with an example or explanation.
• Mistake 7 — Repeating the question's exact wording in the introduction. Fix: paraphrase the prompt using synonyms and different sentence structure — this is one of the first things examiners notice.
• Mistake 8 — Missing or vague overview/conclusion. Fix: in Task 1, an overview is compulsory; in Task 2, end with a short conclusion that restates your position without introducing new ideas.

Vocabulary (Lexical Resource) mistakes

Lexical Resource rewards accuracy and natural range far more than impressive-sounding words used incorrectly. A simple word used correctly always beats a complex word used wrongly.

• Mistake 9 — Inserting memorised 'academic' phrases that don't quite fit the sentence (e.g. using 'plethora' or 'panacea' incorrectly). Fix: only use vocabulary you've seen in context multiple times and understand precisely; when in doubt, choose the simpler, correct word.
• Mistake 10 — Word form errors, such as writing 'the economical growth' instead of 'the economic growth'. Fix: when learning a new word, learn its noun, verb, adjective and adverb forms together, not just one form in isolation.
• Mistake 11 — Repeating the same word for a concept throughout the essay (e.g. 'people' ten times). Fix: build a small bank of synonyms and pronoun substitutes for common essay topics (people/individuals/citizens; problem/issue/challenge).
• Mistake 12 — Using informal or spoken idioms in a formal essay ('a piece of cake', 'kids these days'). Fix: keep register consistently formal — avoid contractions, slang and overly casual phrasing throughout both tasks.

Grammar (Grammatical Range and Accuracy) mistakes

Examiners want to see a range of structures used accurately — not just long, complex sentences. Complexity without control usually lowers your score.

• Mistake 13 — Overcomplicating sentences until the meaning gets lost or the grammar breaks down. Fix: aim for a mix of simple, compound and complex sentences; if a sentence feels hard to control, split it into two clearer ones.
• Mistake 14 — Subject-verb agreement and article errors ('the governments should', 'a informations'). Fix: proofread specifically for articles and agreement in your final two minutes — these are quick, high-frequency errors to catch.
• Mistake 15 — Inconsistent verb tenses within the same paragraph, especially in Task 1 (mixing present and past when describing a fixed-time chart). Fix: decide the correct tense before writing — past for historical data, present for current/general trends — and stay consistent throughout.

A quick self-check before you submit

In the final few minutes of the exam, don't try to fix everything — scan for the errors above in this order: Did I answer every part of the question? Does each paragraph have one clear idea? Have I repeated the same word too often? Are my tenses and articles consistent?

Practising this checklist on timed essays is far more useful than reading about grammar rules in isolation. You can write full-length Task 1 and Task 2 essays and get instant, detailed feedback against these same criteria for free on Bandleep — useful for spotting your own repeated patterns before test day.

Remember that any AI-generated band estimate, on Bandleep or elsewhere, is a practice guide only — not an official IELTS score. Use it to track whether these specific mistakes are decreasing over time.