10 Common IELTS Grammar Mistakes That Lower Your Band Score

Why Grammar Mistakes Cost You Points in IELTS

Your grammar doesn’t need to be perfect to get a high IELTS band score, but certain mistakes appear again and again — and they’re the ones examiners notice right away. When you make these errors frequently, your score for Grammatical Range and Accuracy in Writing and Speaking can drop from a potential 7 to a 6 or even lower.

The good news? These mistakes are easy to fix once you know what to look for. In this lesson, I’ll walk you through 10 of the most common grammar problems that IELTS learners face, with real examples from Writing Task 1, Task 2, and the Speaking test. For each one, you’ll see why it hurts your score, how to correct it, and a simple trick to remember it.

Pick the ones that affect you most and start using them in your next practice session.

10 Common Grammar Mistakes That Lower Your IELTS Score (and Quick Fixes)

1. Subject-Verb Agreement Errors

Even advanced learners slip up here, especially when there’s a long phrase between the subject and the verb.

Example error: ‘The number of international students who choose to study abroad have increased.’ (Task 1)

Correct: ‘...has increased.’ The head noun is ‘number,’ which is singular.

IELTS impact: Examiners notice this mistake immediately. If it appears often, your Grammatical Accuracy score will stay stuck at Band 6 or below.

Quick fix: Find the head noun (the main subject) and ignore the extra words. Ask: Is it one thing or many? Then choose the verb.

2. Missing or Wrong Articles

Speakers of languages that don’t use articles (such as Chinese, Korean, or Japanese) often struggle here. But even learners from article-using languages make this error in IELTS.

Example error: ‘Government should invest more in education.’ (Task 2)

Correct: ‘The government should invest...’ Here, ‘the’ is needed because we mean the government of a particular country (clear from context).

IELTS impact: Article errors can make your writing sound unnatural and affect Coherence as well as Grammar. In Speaking, they can break the flow.

Quick fix: Ask yourself: Is the noun general (no article) or specific (use ‘the’)? For uncountable nouns like ‘pollution,’ never say ‘a pollution.’

3. Preposition Problems

Using the wrong preposition or adding one where it doesn’t belong is common in IELTS.

Example error: ‘The study discusses about the effects of pollution.’ (Task 2)

Correct: ‘...discusses the effects...’ The verb ‘discuss’ takes no preposition.

Another common one: ‘It depends of the situation.’ → ‘It depends on the situation.’

IELTS impact: Frequent preposition errors signal lower lexical resource and grammatical control. They stand out in both Writing and Speaking.

Quick fix: Learn verb+preposition pairs as if they were one word. Keep a personal list of ones you often miss (depend on, interested in, good at, reason for).

4. Wrong Tense for Time Frames in Task 1

In Writing Task 1, you’re often describing data from the past or future. Using the wrong tense immediately tells the examiner you haven’t understood the data.

Example error: ‘The graph shows that the sales increase from 2005 to 2010.’ (But the graph is about a finished past period.)

Correct: ‘...sales increased from 2005 to 2010.’

IELTS impact: In Task 1, tense errors can lower your Task Achievement score because you’re not accurately reporting the information. It also directly hurts Grammar.

Quick fix: Before you write, circle the time words in the question (since 1990, in 2015, by 2020). Decide: past, present, or future? Stick to it.

5. Countable/Uncountable Confusion

This is a classic one. Using ‘a’ with an uncountable noun or making a plural from an uncountable noun can cost you points.

Example error: ‘I have gathered many informations from the survey.’ (Task 1)

Correct: ‘...a lot of information’ or ‘much information.’ Information is uncountable.

IELTS impact: In Writing, it shows limited grammatical range. In Speaking, it can make you pause and stumble.

Quick fix: Memorize common uncountable nouns for IELTS: advice, information, research, equipment, furniture, evidence. They never take ‘a’ and don’t have a plural form.

6. Using the Wrong Word Form

Choosing the right part of speech is crucial, especially in Task 2 where you need to build arguments.

Example error: ‘There is an increase in economic growth because the country is developing economize.’

Correct: ‘...the country is developing economically’ or ‘...economic development.’

IELTS impact: Swapping noun/adjective/adverb forms can weaken your Lexical Resource and Grammar scores together.

Quick fix: When you learn a new word, write down its family: economy (n), economic (adj), economical (adj), economically (adv). Use them in sentences.

7. Messing Up Conditionals

Conditional sentences are great for pushing your grammar score to band 7, but they’re easy to get wrong.

Example error: ‘If the government will invest more, the problem will be solved.’ (Task 2)

Correct: ‘If the government invests more, the problem will be solved.’ We never use ‘will’ in the if-clause of a first conditional.

IELTS impact: Attempting complex grammar but failing can limit you to band 6. Getting it right can push you towards 7.

Quick fix: Practice the patterns: If + present simple, will + base verb (for realistic situations). If + past simple, would + base verb (for hypothetical).

8. Run-On Sentences and Comma Splices

This is a writing-only mistake that makes your essay hard to read.

Example error: ‘The graph shows a sharp rise, it then falls gradually.’

Correct: ‘The graph shows a sharp rise, but it then falls gradually.’ or ‘The graph shows a sharp rise. It then falls gradually.’

IELTS impact: Run-ons and comma splices break the flow and lower both coherence and grammar scores.

Quick fix: If you have two complete ideas with a subject and verb, you need a conjunction (and, but, because) or a semicolon, or split into two sentences. Never use just a comma.

9. ‘More’ + -er Form

This is a small error, but it pops up often in Task 1 when comparing data.

Example error: ‘The graph shows that this year’s profits are more higher than last year’s.’

Correct: ‘...are higher than...’

IELTS impact: Even one of these can mark you as a 6-level user in terms of grammar accuracy.

Quick fix: Golden rule: never use ‘more’ together with an -er adjective (bigger, smaller, higher). Choose one.

10. Unclear Pronoun References

In Speaking and Writing, sentences like ‘When a person gets a new job, it can change their life’ can confuse: what is ‘it’?

Example error: ‘The company improved its services, and they later reported higher profits.’ (Who are ‘they’? The company or the services?)

Correct: ‘...and it later reported higher profits.’ (The company is singular.)

IELTS impact: Unclear pronouns force the examiner to guess what you mean, which hurts coherence and fluency.

Quick fix: After writing a sentence with ‘it,’ ‘they,’ or ‘this,’ read back and ask: Can the examiner immediately tell what this word refers to? If not, repeat the noun.

Your Next Step

Take a recent IELTS Writing task you’ve done (Task 1 or Task 2) and scan it for these 10 errors. Highlight every mistake you find, then rewrite the corrected sentences underneath. This one exercise can quickly sharpen your grammar awareness and help you stop repeating the same errors on exam day.