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Grammatical Range and Accuracy in IELTS Writing, Decoded

IELTS Writing29 August 2026 · 7 min read · WiderAI Team

Grammatical Range and Accuracy is the IELTS Writing criterion that measures two things at once: the variety of sentence structures you can handle (range) and how often you handle them without error (accuracy). It carries a quarter of your writing score, and the boundary that matters most to serious candidates — Band 6 to Band 7 — turns on one specific idea: at Band 7, a good proportion of your sentences must contain no errors at all. Not fewer errors, not smaller errors — sentences that are simply correct from capital letter to full stop.

That reframing changes how you should prepare. Most candidates chase range, bolting on passives, conditionals and inversions because they believe complexity is what examiners count. But an essay stuffed with ambitious structures that each carry an error demonstrates range without accuracy, and it sits at Band 6 alongside the essay that played too safe. The Band 7 writer is doing something less glamorous: mixing simple and complex sentences naturally, and getting most of them completely right.

So the working strategy is: build range only as fast as your accuracy can absorb it, know exactly which errors you personally make, and reserve time at the end of the test to hunt them. This article breaks down what counts as range, what accuracy really demands, and which errors to fix first for the largest score gain.

What does "complex sentences" actually mean?

Not complicated sentences. In the descriptors' sense, a complex sentence is simply one that contains more than one clause — and most of them are structures you already use.

• Subordination: "Although cities keep building roads, congestion keeps getting worse."
• Relative clauses: "Employees who work remotely report higher job satisfaction."
• Conditionals: "If public transport were free, fewer people would drive."
• Noun clauses: "What matters most is whether the policy can be enforced."
• Participle clauses: "Faced with rising costs, many universities have raised fees."

A 30-word sentence held together with four commas and hope is not "more complex" in any rewarded sense — it is usually a punctuation error waiting to be counted. Range also does not mean only complex sentences: the descriptors reward using both simple and complex forms, because that is what skilled writing does. A short, plain sentence after two long ones is a feature. It gives emphasis.

The test of healthy range is variety across the essay, not density within the sentence. If every sentence opens with the subject, or every complex sentence is an "although" sentence, range is narrow even if nothing is wrong. Two or three structure types per paragraph, deployed where the meaning calls for them, is what natural range looks like.

Why do error-free sentences decide Band 7?

Because the descriptors are built around error frequency, and the Band 7 language is explicit: frequent error-free sentences, with grammar and punctuation generally well controlled. At Band 6, errors occur regularly but meaning usually survives; at Band 7, correctness is the norm and errors are the exception. The full descriptors are published on ielts.org, but that contrast is the practical core.

Do the arithmetic on your own writing. A 270-word essay is roughly 15–18 sentences. If ten or more of them are completely clean, you are producing Band 7 evidence; if almost every sentence carries a small flaw — a missing article, a stray comma, an agreement slip — you are producing Band 6 evidence, regardless of how sophisticated the structures are. Small errors are not cheap. They are the whole currency.

This is why self-awareness beats grammar study for candidates above intermediate level. You do not make random errors; you make your errors, drawn from a personal shortlist of three to six patterns. Take five of your marked practice essays, list every error, and tally the repeats. The top three items on that tally are worth more than any grammar book chapter, because eliminating a habitual error cleans dozens of future sentences at once.

Which errors should you fix first?

The highest-frequency errors in IELTS essays are also the most fixable, and several hit speakers of Uzbek, Russian and other article-free languages especially hard.

Articles

The most common error category for most candidates. Two rules resolve the bulk of cases: a singular countable noun almost never stands alone — it needs a/an, the, or a plural — and the marks what reader and writer can both identify ("the government" of the country under discussion; "governments" in general). When writing about a category in general, prefer the bare plural: "Universities should lower fees", not "The universities should lower the fees".

Subject–verb agreement

The trap is distance: "The number of students who fail these exams is rising" — the verb agrees with "number", not with the nouns crowding next to it. Whenever a subject and its verb are separated by a long phrase, check them as a pair during proofreading.

Tense consistency

Essays about general truths live in the present simple, and most tense errors are unmotivated drift into past or future. Shift tense only when the meaning shifts — a past cause ("Twenty years ago, few households owned a computer"), a predicted consequence ("this trend will accelerate"). If you cannot name the reason for a tense change, undo it.

Punctuation, especially the comma splice

Punctuation is assessed inside this criterion. The comma splice — "Traffic is increasing, the government must act" — is the most damaging habit because it turns two correct clauses into one error. Fix it with a full stop, a semicolon, or a connector: "Traffic is increasing, so the government must act." Also mind the comma after a fronted subordinate clause: "Although fees are high, students keep enrolling."

How do you build range without losing accuracy?

Add one structure at a time, and rehearse it to reliability before adding the next. Pick a structure just beyond your comfort zone — say, the "if + past, would" conditional — and write ten sentences with it across different topics until it comes out clean without thought. Then, in your next practice essay, use it once or twice where it genuinely fits. That is how range grows in a way an examiner can reward: as controlled variety, not as gambling.

A concrete Band 7 sentence portfolio to make automatic: one concession sentence ("Although X, Y"), one relative clause, one unreal conditional, one passive where the agent is unimportant ("This policy has been adopted in several countries"), and one short emphatic simple sentence. An essay that deploys those five accurately, alongside plain correct sentences, demonstrates everything the range half of the criterion asks for.

The same criterion, with the same name, applies to speaking — judged live, without proofreading time — so testing your grammar under real-time pressure in an IELTS speaking mock test exposes which structures are truly automatic and which only survive on paper. For the other three writing criteria, the companion guides on the WiderAI blog follow the same plain-English approach.