Short answer: Grammatical Range and Accuracy is 25% of your Writing band and it marks two things that pull against each other — how varied your sentence structures are, and how many of your sentences are error-free.
This is why a careful candidate who writes only short, correct sentences lands at band 6, and why an ambitious candidate whose complex sentences break lands there too. Band 7 needs both: a variety of complex structures and frequent error-free sentences.
Most candidates try to fix this criterion by removing errors. If your sentences are already mostly simple, that raises accuracy and leaves range where it was — so the band does not move.
The band ladder, in plain English
| Band | Descriptor, in short | What that looks like |
|---|---|---|
| 5 | Limited range; attempts complex sentences but they are "less accurate than simple sentences"; frequent errors, and punctuation may be faulty | Simple sentences that work, complex attempts that do not, and commas joining independent clauses. |
| 6 | A mix of simple and complex forms; some errors in grammar and punctuation, but they "rarely reduce communication" | Real complex sentences, several per essay, each with something slightly wrong — a missing article, a tense slip, a comma splice. |
| 7 | "A variety of complex structures"; "frequent error-free sentences"; good control with a few errors | More than one type of complex sentence, used deliberately, with most sentences clean. |
| 8 | "A wide range of structures"; "the majority of sentences are error-free"; "only very occasional errors or inappropriacies" | Structures chosen for effect, not for display. Errors are slips, not patterns. |
Notice what band 7 asks for: "a variety of complex structures". Not one complex structure repeated. A candidate who writes fourteen "Although…" sentences has repetition, not range — and in our marking that is a band 6 script.
What actually counts as a complex structure
"Complex" is a grammatical term, not a compliment. It means a sentence containing a subordinate clause. Length has nothing to do with it.
| Structure | Model sentence | The error it usually produces |
|---|---|---|
| Relative clause (non-defining) | "Congestion charging, which London introduced in 2003, cut traffic sharply." | Using "that" for a non-defining clause, or dropping the commas. |
| Adverbial clause of concession | "Although the scheme is unpopular, it has reduced emissions." | "Although… but…" — one connector per relationship, not two. |
| Conditional (second or third) | "If fares were subsidised, ridership would rise." | Mixing the tenses across the two halves. |
| Participle clause | "Faced with rising costs, many commuters switched to buses." | A dangling modifier — the participle must describe the subject of the main clause. |
| Noun clause as subject | "What governments underestimate is the cost of enforcement." | Adding a second subject: "What governments underestimate it is…". |
| Passive for process | "The raw material is then transferred to a drying chamber." | Using the passive everywhere, which reads as evasive in Task 2. |
Two of those six, used accurately and repeatedly, will do more for the band than a rare structure attempted once. For Task 1 Academic specifically, the passive and the participle clause carry most of the process-diagram language — our process diagram guide works through them in context.
Punctuation is marked here, and comma splices are the pattern
Punctuation appears explicitly in the descriptors from band 5 upward, and one error dominates: joining two independent clauses with a comma.
| Fix | Result | What it buys |
|---|---|---|
| Full stop | "Cars are expensive. Many families rely on buses." | Accuracy only |
| Coordinator | "Cars are expensive, so many families rely on buses." | Accuracy only |
| Subordinator | "Because cars are expensive, many families rely on buses." | Accuracy and range |
| Semicolon | "Cars are expensive; many families rely on buses." | Accuracy, plus punctuation range if used sparingly |
The third fix is the one to prefer, because it repairs the accuracy error and adds a complex structure. That is the shape of this whole criterion: the best repairs buy range and accuracy at once.
The error-density reality
IELTS does not publish an error count per band, and any site that gives you one is inventing it. What the descriptors say is comparative: band 7 has "frequent" error-free sentences, band 8 a "majority" of them.
Our practical read from marking is that band 7 scripts tend to run around half their sentences clean and band 8 clearly more than half — treat that as an orientation, not a threshold.
What follows from it is useful regardless of the number. Accuracy is judged per sentence, not per error. One sentence with three errors costs you one clean sentence; three sentences with one error each cost you three.
So the highest-value edit in a timed essay is finding the single messiest sentence and splitting it, not hunting articles across the whole script.
The five errors that account for most band 6 scripts
- Articles. A missing "the" before a specified noun, or "a" before a singular countable. The highest-frequency error in the test and the least damaging per instance — which is why it is rarely worth your last five minutes.
- Subject-verb agreement across a long subject. "The number of students who enrol in evening courses have risen" — the subject is "the number", so it is "has".
- Tense consistency in Task 1. A chart with a date in the past is past tense throughout; a projection is future. Drifting between them mid-paragraph is a pattern error, not a slip.
- Comma splices, as above.
- Countable and uncountable nouns. "researches", "advices", "informations", "equipments". These are also charged under Lexical Resource as word-formation errors, so the habit is billed twice.
The fastest route from 6 to 7
- Pick two complex structures from the table above that you do not currently use, and drill them until they are automatic. Range is a variety requirement — two new reliable structures satisfies it faster than one exotic one.
- Convert your comma splices into subordinate clauses rather than full stops. Same edit, two criteria.
- Proof by sentence, not by error. In your last five minutes, find the worst sentence and rewrite it as two.
- Fix your own pattern, not the generic list. Most candidates repeat three errors. Find yours from a marked essay, then stop reading general grammar advice.
- Leave articles until last. Correct, but the lowest return per minute of any edit here.
The study-list version of this — the structures themselves, with drills — is in grammar for IELTS band 7. This page is about how the criterion is marked, which is a different question and usually the more useful one once you have plateaued.
To find your own three repeating errors, the Writing Checker gives Grammatical Range and Accuracy as its own band with the sentences it marked down, and the Band 8 Trainer marks a single paragraph at a time, which is short enough that you can actually see the pattern.