Scoring reference: official IELTS Writing descriptors and assessment criteria. The examples here illustrate writing choices; they are not independently assessed complete scripts.
Grammatical Range and Accuracy considers both variety and control within a single criterion. Range asks you to use a variety of sentence structures, including complex ones. Accuracy concerns the control and communicative effect of your grammar and punctuation. The collision comes when a candidate attempts an ambitious complex sentence, loses control midway, and the whole structure collapses. The examiner does not reward the ambition. They penalise the error.
Why simple sentences alone cannot get you to Band 7
A Band 7 requires a 'variety of complex structures'. If every sentence in your essay is simple (one independent clause, one idea), that alone does not demonstrate the range expected at higher levels. You need to mix in structures that show you can handle relationships between ideas inside a single sentence. But you do not need to make every sentence complex. There is no prescribed percentage of complex sentences. Let the ideas determine the structure, and check that the result remains clear.
Four complex structures that work reliably
You do not need a dozen sentence types. Four structures cover almost every relationship you will need in Task 2, and mastering these four is safer and more effective than attempting structures you half-know.
- Subordinate clause (although, because, while, whereas, if, unless): 'Although private cars are convenient, they impose heavy costs on the environment and public health.' The subordinate clause sets up a contrast or condition; the main clause delivers the point.
- Relative clause (who, which, that, whose, where): 'Governments that invest early in renewable energy tend to see long-term economic gains.' The relative clause adds precision by narrowing who or what you mean.
- Conditional sentence (if, unless, provided that, as long as): 'If cities do not invest in public transport now, congestion will become unmanageable within a decade.' Conditionals let you project consequences, which is especially useful for problem-solution essays.
- Participle phrase (replacing a full clause with a shorter construction): 'Faced with rising congestion, many cities have introduced congestion charges.' The participle phrase ('Faced with...') replaces a longer clause ('Because they are faced with...') and tightens the sentence.
Original: simple sentencesCars cause pollution. They also cause congestion. Governments should invest in public transport. This would reduce both problems.
Rewrite: mixed structuresWhile private cars contribute significantly to pollution and congestion, investing in public transport would reduce both problems simultaneously.
Four choppy simple sentences become one controlled complex sentence. The structure is 'subordinate clause + main clause'. No complicated vocabulary. No risk of collapse. Just clear logic inside a clean structure.
The collapse pattern and how to avoid it
The most common complex sentence failure is a candidate piling clause on top of clause until the reader loses the thread. The essay equivalent of taking on too much weight at the gym. As a practice exercise, start with one subordinate clause and one main clause. Add complexity only when it helps the meaning and you can control the structure; a clause count cannot guarantee a band.
Original: clause errorAlthough many governments have introduced policies to reduce carbon emissions but the progress is slow because of economic interests which are often prioritised over environmental concerns by politicians who are elected on short-term platforms.
Rewrite: controlled clausesAlthough many governments have introduced policies to reduce carbon emissions, progress is slow because economic interests are often prioritised over environmental concerns.
The original combines 'although' and 'but' incorrectly and adds several clauses. The rewrite keeps the main point and removes that error. These are illustrative sentence edits, not independently scored scripts.
Relative clauses, subordination and sentence combining, ten items with instant feedback.
Try the complex sentences drillAccuracy is not boring
A common fear is that playing it safe with grammar will bore the examiner. The reality is that a clean, accurate complex sentence scores higher than a broken, ambitious one every single time. For the grammar mistakes that most often sabotage accuracy, our grammar mistakes guide breaks down the six patterns.
After writing an essay, underline every complex sentence. If a sentence becomes hard to follow, try splitting it. If any complex sentence confuses you when you re-read it, the examiner will be confused too. Simplify it.
If you want to see your Grammatical Range and Accuracy scored against the descriptor, grade an essay and check where the balance of range and accuracy is landing for your writing.