IELTS Grammatical Range and Accuracy: Complex Sentences That Score

Most learners I talk to believe that a high grammar score means long, clever sentences. It does not. IELTS grammatical range and accuracy is one of the four Writing criteria, and it rewards two things at once: a mix of sentence forms and sentences that are correct. A learner who writes ten ambitious sentences with ten errors usually scores lower than one who writes six controlled complex sentences and four clean simple ones.

This post shows what the criterion asks for, which four structures give the best return, and a drill you can run in two weeks.

What the examiner actually looks for

The public band descriptors for Grammatical Range and Accuracy describe the pattern clearly. Around Band 6, a candidate uses a mix of simple and complex sentence forms, and makes some errors that rarely reduce communication. At Band 7, the candidate uses a variety of complex structures, produces frequent error-free sentences and has good control of grammar and punctuation. Below that, range is limited and errors start to make the reader work.

Two details matter in practice:

• "Frequent error-free sentences" is a measurable target. Reread your own essay and count the sentences with zero mistakes. If fewer than half are clean, range is not your problem yet.
• "Variety" is not "length". A sentence with three clauses joined by and is long but not varied. Subordination, relative clauses and conditionals are what count as complex.

Remember the clock as well. Writing is 60 minutes for two tasks: Task 1 needs at least 150 words and Task 2 at least 250, and Task 2 is worth twice as much. You do not have time to polish every sentence, so you need a small set of structures you can produce correctly under pressure.

Fix accuracy before you add range

Before learning anything new, remove the errors you repeat. In most Vietnamese and Japanese learners' essays I have seen, the same few appear again and again:

• Subject-verb agreement after a long subject: The number of students who study abroad are increasing. (The subject is number, so it is is.)
• Missing or wrong articles: Government should invest more in public transport. (It needs The government, or Governments.)
• Tense drift inside one paragraph, especially when describing a past trend and then a future prediction in Task 1.
• Comma splices: Technology is useful, it saves time. (Use a full stop, a semicolon, or because.)

Keep a list of your own top three. Check for exactly those on the last five minutes of every practice essay. This single habit usually lifts accuracy faster than any new grammar topic.

Four structures worth learning first

These four appear naturally in both Task 1 and Task 2, and they are easy to check for errors.

1. Relative clauses. They add information without starting a new sentence.

Cities that invest in cycling lanes tend to see fewer short car journeys.

The watch-out: that and which are not interchangeable when you add a comma. A comma before which adds extra information; no comma defines the noun.

2. Concession with although, while or whereas. This is the most useful structure for Task 2 because it shows both sides in one sentence.

Although online courses are cheaper, they rarely give students the same speaking practice.

The watch-out: never write Although... but... in the same sentence. One connector is enough.

3. Conditionals for cause and consequence. Second and first conditionals fit argument writing best.

If governments taxed sugary drinks more heavily, consumption would probably fall.

The watch-out: the tense pairing. If governments will tax... is wrong; after if, use the present or past simple.

4. Participle phrases. These are very common in Task 1 and make your reporting sound less mechanical.

Sales peaked in 2015 at 40,000 units, falling sharply over the following three years.

The watch-out: the -ing phrase must refer to the subject of the main clause. Falling sharply, the chart shows... is wrong because the chart did not fall.

One paragraph, rewritten

Here is a typical Band 5.5 body paragraph:

Many people use social media. It is popular with young people. It can be bad for their health. They spend too much time on it. They sleep less.

Every sentence is correct, but there is no variety and no logic between ideas. A rewrite that uses the four structures above:

Social media, which is especially popular with young people, can damage their health if they spend too much time on it. Although many teenagers see these platforms as harmless entertainment, those who scroll late at night often sleep less, falling behind at school as a result.

The rewrite uses a relative clause, a conditional, a concession and a participle phrase, and it is shorter than the original. The ideas also now depend on each other, which helps Coherence and Cohesion too.

Where complex sentences go wrong

Three failure patterns cost the most marks:

• Overloading. Four or five clauses in one sentence usually collapse in the middle. If you have to re-read your own sentence to find the subject, split it.
• Memorised structures that do not fit. Examiners recognise a template dropped into the wrong topic. Choose the structure because the idea needs it.
• Ignoring punctuation. Missing commas after fronted clauses (Although it is cheap, ...) and wrongly placed commas around defining relative clauses are counted as errors, even when the grammar is otherwise fine.

A two-week drill

You do not need a grammar book. You need repetition on four structures.

1. Days 1–3: Write five sentences for each structure about topics you know (your job, your city, your studies). Check each one against the watch-out above.
2. Days 4–7: Take one old Task 2 paragraph and rewrite it with at least one of each structure, without increasing its word count by more than 20%.
3. Days 8–12: Write one full Task 2 essay per day in 40 minutes. In the final five minutes, only hunt for your personal top-three errors.
4. Days 13–14: Compare your first and last paragraph. Count error-free sentences in each.

Getting someone else's eyes on your sentences helps, because you are blind to your own repeated mistakes. A teacher, a study partner or an AI grader can all point them out. On Toey you can submit a Writing task and get feedback on all four criteria within a few minutes, but the grade is an AI estimate rather than an official band, so treat it as a pointer to what to fix, not as a prediction.

Quick self-check

Before you submit any practice essay, ask yourself:

• Did I use at least three different sentence forms in each paragraph?
• Can I point to a relative clause, a concession and a conditional in the essay?
• Are at least half of my sentences completely error-free?
• Does every long sentence have one clear subject and verb?

If the answer to the last two is no, do not add new structures yet. Clean up first, then expand.

Checked on 18 October 2026.

Practice IELTS Writing with AI feedback on Toey