Most candidates who plateau at Band 6 in IELTS Writing Task 2 aren't making obvious mistakes. Their grammar is mostly correct, their vocabulary is reasonable, and their essay has an introduction, body paragraphs, and a conclusion. And yet the score doesn't move. The reason almost always comes down to not understanding what the four official scoring criteria are actually measuring — and writing to impress a general reader instead of writing to satisfy an examiner working from a specific rubric.
Here's what each criterion actually checks, what separates a Band 6 essay from a Band 7 or 8 essay, and where most Iranian test-takers specifically lose marks.
The four criteria, and why each is worth exactly 25%
Every Task 2 essay is graded on four criteria, each contributing an equal quarter of the final Task 2 band. That equal weighting matters: a beautifully written essay that doesn't fully answer the question is capped by Task Response, no matter how impressive the grammar or vocabulary is elsewhere.
Task Response 25%
This measures whether you've actually answered the specific question asked — not a related question, and not just the topic in general. Examiners check whether every part of the prompt is addressed, whether your position is clear and maintained throughout (not vague or contradictory), and whether your ideas are developed with explanation and example rather than just stated and left there.
This is the single most common reason strong writers stay at Band 6: they write fluently about the topic without directly answering what was asked, or they list three ideas in one sentence each instead of developing one or two ideas properly.
Coherence and Cohesion 25%
This is about whether a reader can follow your argument without effort. It covers paragraph structure (one central idea per paragraph, introduced clearly), and how you connect ideas — through linking words, but also through pronouns and reference words that avoid repeating the same noun over and over.
The most common trap here isn't too few linking words — it's relying only on "Firstly, Secondly, Finally" and "Moreover, Furthermore, In addition" throughout the whole essay. Examiners notice mechanical, repetitive linking immediately, and it caps this criterion regardless of how logical the underlying argument is.
Lexical Resource 25%
This measures vocabulary range and accuracy — not just whether you know "big" words, but whether you use them correctly and appropriately for the context. A Band 7+ essay uses less common vocabulary naturally, with correct collocations (word combinations that sound right to a native reader), and shows awareness of style — knowing that some words fit an academic essay and others don't.
The most damaging pattern here is using an advanced word incorrectly in an attempt to sound sophisticated. A correctly used simple word scores higher than an impressive word used wrong.
Grammatical Range and Accuracy 25%
This checks both variety (are you only using simple sentences, or a genuine mix of simple, compound, and complex structures) and accuracy (how many errors, and how much they interfere with understanding). Band 7+ requires a real range of complex structures — relative clauses, conditionals, passive voice where appropriate — used with mostly correct grammar, not just one or two memorized templates repeated throughout the essay.
What actually separates Band 6 from Band 7
In my 25+ years of correcting essays, the gap between these two bands is rarely about knowledge. It's about execution under time pressure. Here's the pattern I see most often:
Typical Band 6 essay
- Covers the topic, but only partially answers the specific question asked
- States 3-4 ideas briefly instead of developing 2 ideas fully
- Relies on basic linking words throughout ("Firstly," "In conclusion")
- Vocabulary is accurate but mostly general, not precise or field-specific
- Mostly simple and compound sentences, with occasional complex ones that contain errors
Typical Band 7+ essay
- Directly and fully addresses every part of the prompt
- Develops fewer ideas, but explains and extends each one with reasoning or example
- Uses varied cohesive devices — reference words, varied connectors, not just sequencing words
- Vocabulary is precise, with natural collocations and appropriate register
- A genuine range of complex structures, mostly error-free
Where Iranian candidates specifically lose marks
Teaching Iranian students for over two decades, I see the same handful of patterns repeat far more than random chance would suggest:
- Direct translation of Persian sentence structure. Persian allows a flexibility in word order and clause-joining that English doesn't. Essays translated mentally from Persian often read as grammatically odd to an examiner even when no single rule is technically broken.
- Memorized "template" phrases used mechanically. Phrases like "It is often said that..." or "There are several reasons for this" are fine occasionally, but when every paragraph opens with a memorized template, it signals a formulaic essay rather than genuine argument — and caps Coherence and Cohesion.
- Over-editing for "big words" at the expense of clarity. A rush to insert impressive vocabulary often comes at the cost of precise meaning. Examiners are trained to notice this pattern specifically.
- Running out of time on Task 2 because Task 1 took too long. Task 2 is worth twice as much as Task 1, but candidates under time pressure often spend disproportionate time perfecting Task 1. This isn't a writing-skill problem — it's a time-management problem with a real score cost.
The part self-study can't fix
You can memorize all four criteria and still not know which one is actually capping your score — because that requires someone reading your specific essay against the specific rubric, not a general checklist. This is the single biggest reason candidates plateau even after months of independent practice: they're missing the one piece of feedback that tells them exactly which criterion is holding them back, and why.
Get your essay evaluatedA realistic path from Band 6 to Band 7+
Based on what I've seen work consistently: focus on fewer ideas developed more fully rather than more ideas stated briefly, deliberately vary your linking devices instead of relying on the same five, and get every practice essay checked against the actual rubric rather than just "does this sound good." Most students who follow this approach see real movement within 8 to 12 weeks of focused practice — not because the content knowledge changes, but because the execution under exam conditions does.