Common Grammar Mistakes in IELTS Writing and How to Fix Them
Grammar accounts for 25% of your IELTS Writing score through the Grammatical Range and Accuracy criterion. Examiners assess both the range of grammatical structures you use and the accuracy with which you use them. A test-taker who uses only simple sentences perfectly will score lower than one who attempts complex structures with occasional errors — but a test-taker who attempts complex structures with frequent errors will also score poorly.
The most effective strategy is to identify your recurring mistakes and eliminate them. Most test-takers have 3-5 persistent grammar errors that appear in every essay they write. Fixing these patterns can push your Grammatical Range score up by a full band.
1. Subject-Verb Agreement
This is the most common grammar error in IELTS Writing, particularly when the subject and verb are separated by a prepositional phrase.
Wrong: "The number of students who study abroad have increased."
Correct: "The number of students who study abroad has increased."
The subject is "the number" (singular), not "students" (plural). The phrase "of students who study abroad" sits between the subject and verb, causing confusion. Always identify the true subject of the sentence.
Wrong: "One of the main reasons are financial pressure."
Correct: "One of the main reasons is financial pressure."
2. Articles (a, an, the)
Article errors are among the most frequent in IELTS, particularly for test-takers whose first language does not use articles (Chinese, Japanese, Korean, Russian, Turkish, Arabic).
Wrong: "Education is important factor in development."
Correct: "Education is an important factor in development."
Wrong: "The education should be free for all."
Correct: "Education should be free for all."
Use "the" for specific things ("the government of Australia"), "a/an" for non-specific countable nouns ("a student"), and no article for general uncountable nouns or plural concepts ("education," "technology," "children").
3. Run-On Sentences
A run-on sentence joins two independent clauses without proper punctuation or a conjunction.
Wrong: "Many people disagree with this policy they believe it restricts freedom."
Correct: "Many people disagree with this policy because they believe it restricts freedom."
Also correct: "Many people disagree with this policy. They believe it restricts freedom."
Solutions: Add a conjunction (because, and, but, so), use a semicolon, or split into two sentences. Run-on sentences are a significant error at band 6 and above because they indicate a lack of control over sentence boundaries.
4. Comma Splices
A comma splice joins two independent clauses with only a comma — no conjunction.
Wrong: "Technology has advanced rapidly, it has changed how we communicate."
Correct: "Technology has advanced rapidly, and it has changed how we communicate."
Also correct: "Technology has advanced rapidly; it has changed how we communicate."
5. Incorrect Tense Usage
Tense errors are particularly common in Task 1 when describing data over time, and in Task 2 when discussing hypothetical situations.
Wrong: "If the government will invest more in education, society benefited."
Correct: "If the government invested more in education, society would benefit."
For second conditional (hypothetical present/future): if + past simple, would + base verb. For third conditional (hypothetical past): if + past perfect, would have + past participle.
6. Uncountable Nouns
Certain common IELTS vocabulary words are uncountable and cannot be used with "a" or in plural form.
Wrong: "The government should provide more informations."
Correct: "The government should provide more information."
Commonly misused uncountable nouns in IELTS: information, advice, knowledge, research, evidence, equipment, furniture, traffic, pollution, accommodation, progress, homework, vocabulary
7. Word Order in Complex Sentences
Wrong: "Is important that governments take action on climate change."
Correct: "It is important that governments take action on climate change."
English requires a subject in every clause. When the real subject comes after the verb, use "it" as a placeholder subject (formal/dummy subject).
8. Preposition Errors
Preposition errors are extremely common because preposition usage is largely idiomatic — it must be memorized rather than learned through rules.
Wrong: "This depends of many factors."
Correct: "This depends on many factors."
Common preposition errors: depend on (not of), result in (not to), consist of (not from), contribute to (not for), responsible for (not of).
9. Relative Clause Errors
Wrong: "People which live in cities face more pollution."
Correct: "People who live in cities face more pollution."
Use "who" for people, "which" for things, and "that" for either. Using "which" for people is a common error that marks your writing as non-native at even basic levels.
10. Passive Voice Errors
Wrong: "The problem can solved by the government."
Correct: "The problem can be solved by the government."
Passive voice requires: subject + form of "be" + past participle. Omitting "be" is a frequent error, especially in modal constructions (can be done, should be addressed, must be considered).
11. Parallel Structure
Wrong: "The benefits include saving money, convenience, and it reduces pollution."
Correct: "The benefits include saving money, increasing convenience, and reducing pollution."
When listing items in a series, all items must follow the same grammatical pattern. If the first item is a gerund (saving), all items should be gerunds.
12. Sentence Fragments
Wrong: "Because many people cannot afford university fees. This is a major problem."
Correct: "Because many people cannot afford university fees, this is a major problem."
A clause beginning with "because" cannot stand alone — it is a dependent clause that must be attached to an independent clause. Other fragments are caused by starting sentences with "Which," "Although," or "While" and then ending the sentence after the dependent clause.
How to Identify Your Errors
The fastest way to identify your grammar patterns is to write three essays on different topics and then review them specifically for grammar — not content, not vocabulary, just grammar. Mark every error with a colored pen. You will likely notice that 70-80% of your errors fall into just 2-3 categories from the list above.
Once you know your error patterns, create practice exercises targeting those specific areas. If you consistently make article errors, practice adding articles to article-free sentences. If you make subject-verb agreement errors, practice identifying the true subject in complex sentences.
WitPrep's AI Essay Grader provides detailed feedback on grammatical accuracy, highlighting specific error types and patterns. Submit practice essays regularly to track which grammar areas need the most attention.
Once you have fixed your grammar errors, focus on improving your linking words and cohesion for a further score boost. For a full picture of how grammar affects your score, read how IELTS is scored.
Continue your IELTS prep on WitPrep
These free WitPrep IELTS hub pages give you the practice material referenced in this article — every prompt is original, every page has interactive tools (AI essay grader pre-fill, speaking timers, band calculator, TTS playback, MediaRecorder self-review and PDF download).