IELTS Writing Grammar Guide: Most Common Mistakes to Avoid

When preparing for the IELTS Writing test, many candidates focus on vocabulary, ideas, and structure. While these are crucial, grammar often becomes the hidden stumbling block that prevents test-takers from achieving a high band score. Examiners pay close attention to grammatical range and accuracy, and repeated mistakes can lower your score significantly. This guide explores the most common grammar mistakes in IELTS Writing, why they matter, and how to avoid them.

Why Grammar Matters in IELTS Writing

In the IELTS Writing Band Descriptors, “Grammatical Range and Accuracy” is one of the four key criteria. To achieve Band 7 or higher, candidates must demonstrate flexibility in sentence structures and maintain a high level of accuracy. Frequent errors in tense, articles, prepositions, or sentence structure make your writing less clear and less academic. By mastering grammar, you not only avoid penalties but also express ideas with precision and sophistication.

1. Subject-Verb Agreement Errors

One of the most frequent mistakes is incorrect subject-verb agreement.

Example of mistake:
❌ Many people believes that technology is harmful.

Correct form:
✅ Many people believe that technology is harmful.

Tip: Always identify whether the subject is singular or plural. Be especially careful with subjects like “everyone,” “each,” or “the number of,” which are singular, even if they sound plural.

2. Misuse of Articles (a, an, the)

Articles are notoriously difficult for IELTS candidates, especially for those whose first language does not use them.

Examples:
❌ He is studying in university.
✅ He is studying at a university.

❌ The pollution is big problem in cities.
✅ Pollution is a big problem in cities.

Tip: Use “a/an” for non-specific, countable nouns. Use “the” for something specific or unique. Omit articles when speaking about general, uncountable nouns.

3. Incorrect Tense Usage

IELTS essays often require you to discuss general truths, past events, and future predictions. Many candidates confuse tenses or use inconsistent forms.

Examples:
❌ In the past, people uses handwritten letters to communicate.
✅ In the past, people used handwritten letters to communicate.

❌ If governments will provide more funding, education improve.
✅ If governments provide more funding, education will improve.

Tip: Pay attention to timeline consistency. Use simple present for facts, past tense for history, and future forms when making predictions.

4. Sentence Fragments and Run-On Sentences

Another major issue is writing incomplete sentences or joining too many ideas without proper punctuation.

Examples:
❌ Because people are moving to cities. (incomplete sentence)
✅ Cities are becoming overcrowded because people are moving to them.

❌ Technology has benefits it also creates problems for society. (run-on sentence)
✅ Technology has benefits, but it also creates problems for society.

Tip: Every sentence should have a subject and a verb. Use conjunctions, commas, and periods appropriately to separate ideas.

5. Confusing Singular and Plural Nouns

Mixing up singular and plural forms reduces clarity.

Examples:
❌ Many student find it difficult to balance study and work.
✅ Many students find it difficult to balance study and work.

Tip: Always check if your noun needs an “s” at the end. Watch out for uncountable nouns like “information,” “advice,” and “furniture,” which should not be pluralized.

6. Misplaced Modifiers

Placing adjectives or adverbs in the wrong spot makes sentences awkward.

Example:
❌ Students can only improve their skills if they practice regularly grammar.
✅ Students can only improve their grammar skills if they practice regularly.

Tip: Keep modifiers close to the words they describe.

7. Overuse of Passive Voice

While passive voice is useful in academic writing, excessive use can make your essay unclear.

Example:
❌ It is believed by many people that social media is harmful.
✅ Many people believe that social media is harmful.

Tip: Use active voice when possible for direct and engaging sentences.

8. Incorrect Prepositions

Prepositions are small but tricky. Incorrect use makes your writing sound unnatural.

Examples:
❌ He is good in English.
✅ He is good at English.

❌ We discussed about the issue.
✅ We discussed the issue.

Tip: Learn collocations—common word + preposition combinations.

9. Overusing Simple Sentences

Candidates aiming for Band 7 or higher must use a variety of sentence structures. Using only short, simple sentences lowers your score.

Example:
❌ The environment is important. People should protect it. Governments should make laws.
✅ The environment is important, so people should protect it, and governments should create strict laws to support conservation.

Tip: Use a mix of simple, compound, and complex sentences.

10. Word Form Errors

Sometimes students use the wrong form of a word—noun instead of verb, adjective instead of adverb, etc.

Examples:
❌ The government should act effective to reduce pollution.
✅ The government should act effectively to reduce pollution.

Tip: Learn families of words (develop → development → developmental). Check if you need an adjective, adverb, noun, or verb.

Strategies to Improve Grammar for IELTS Writing

1. Review Common Mistakes
   Make a personal error log of your writing. Note your recurring mistakes and review them before every practice essay.

2. Practice with Grammar-Focused Exercises
   Websites, apps, and IELTS preparation books often include targeted grammar drills.

3. Read High-Quality Essays
   Reading model IELTS essays and academic articles helps you internalize correct grammar usage.

4. Write and Edit Regularly
   Writing daily and editing your work critically will reduce errors over time.

5. Get Feedback
   Ask a teacher, tutor, or use AI-based grammar tools to check your writing.

6. Focus on Accuracy First, Then Range
   Examiners prefer fewer complex sentences with correct grammar over many complex sentences with mistakes.

Conclusion

Grammar is not just about avoiding mistakes—it’s about communicating your ideas clearly and persuasively. In IELTS Writing, even small errors can affect your band score, especially if they occur repeatedly. By paying attention to subject-verb agreement, articles, tenses, sentence structure, prepositions, and word forms, you can strengthen your writing and move closer to your target score. With practice, awareness, and careful editing, you can turn grammar into one of your strongest assets in the IELTS test.

What does “grammar” cover in the IELTS Writing test?

In IELTS Writing, grammar refers to both range (the variety of structures you use) and accuracy (how correctly you use them). Examiners assess your control of tense, subject–verb agreement, articles, prepositions, sentence boundaries (run-ons and fragments), word forms, and complex structures such as conditionals, relative clauses, and passive/active voice. A strong performance shows flexible sentence patterns with minimal error density—especially in frequently repeated structures.

Which grammar mistakes reduce scores most often?

Common score killers include incorrect subject–verb agreement (e.g., “many people believes”), misused articles (“a pollution”), tense inconsistency, run-on sentences, sentence fragments, wrong prepositions (“discuss about”), overuse of passive voice, mis-modified phrases, plural/uncountable noun confusion (“informations”), and wrong word forms (“act effective”). Repeated errors—even small ones—lower your band more than a single occasional slip.

How can I quickly check subject–verb agreement?

First, locate the real subject (ignore phrases like “along with,” “as well as,” or relative clauses). Then match the verb to the number of that subject. Watch out for traps: “everyone,” “each,” and “neither” are singular; “a number of” is plural, but “the number of” is singular. When the subject is a complex noun phrase (“A range of policies that address emissions is/are…”), focus on the head noun: “range” (singular) vs. “policies” (plural). Read the sentence aloud: the ear often catches mismatches.

How should I choose between active and passive voice?

Prefer active voice for clarity and concision: “Governments should invest in public transport.” Use passive when the doer is unknown, unimportant, or obvious from context: “Public funds are wasted when oversight is weak.” A balanced essay uses both, but heavy, automatic passives (“It is believed by many…”) can sound wordy and reduce readability. Revise passives that hide weak verbs (“be,” “get”) and replace them with specific active verbs (“tighten,” “enforce,” “subsidize”).

How do I avoid run-on sentences and sentence fragments?

A run-on happens when independent clauses are joined with only a comma or nothing: “Cities are growing they require more housing.” Fix it by using a period, semicolon, or coordinating conjunction: “Cities are growing, so they require more housing.” A fragment lacks a full subject–verb idea: “Because public transport is unreliable.” Complete it: “Public transport is unreliable, so commuters prefer cars.” During editing, scan each sentence for a finite verb and a complete thought.

What are the most frequent article errors and how can I fix them?

Use “a/an” for a non-specific, singular, countable noun (“a policy”), “the” for something specific or previously mentioned (“the policy introduced in 2020”), and zero article for general, uncountable, or plural concepts used generically (“Education is essential”; “Policies shape outcomes”). Remember common patterns: “at university,” “in the short term,” “on the other hand.” Build a mini-checklist for your final pass: proper nouns (no article), unique nouns (often “the”), and abstract nouns (often zero article unless specified).

How can I keep tenses consistent across paragraphs?

Decide the time frame of each idea: use the present simple for general truths and trends (“Urbanization increases demand”), the past tense for historical reference (“In the 1990s, planners relied on…”), and appropriate future or modal forms for predictions and recommendations (“This policy will reduce emissions,” “Governments should incentivize…”). When describing data, match the tense to the chart’s period: past data → past simple; timeless summary → present simple. If you shift time frames, signal them with adverbials (“historically,” “currently,” “in the coming years”).

What is the best way to handle prepositions and collocations?

Memorize high-frequency academic collocations: “impact on,” “benefit from,” “rely on,” “invest in,” “responsible for,” “capable of,” “good at,” “result in,” “result from.” Keep a personal collocation bank sourced from your practice essays and model answers. When unsure, prefer simpler rephrasing (“discuss the problem” instead of “discuss about the problem”). During proofreading, circle verbs and adjectives, then check the prepositions that follow them.

How can I increase grammatical range without increasing errors?

Upgrade safely by layering familiar structures: add dependent clauses (“because,” “although,” “while”), relative clauses (“which,” “that”), and controlled conditionals (“If governments subsidize fares, ridership will increase”). Combine ideas with coordinating conjunctions for flow (“and,” “but,” “so,” “yet”). Use participle phrases sparingly (“Given rising costs, households cut spending”), and nominalization where natural (“the introduction of a carbon tax”). Prioritize accuracy: it is better to use a few well-formed complex sentences than many error-prone ones.

What are effective editing routines for error reduction?

Adopt a three-pass method: (1) Structure pass—check paragraph logic and topic sentences; (2) Sentence pass—look for run-ons, fragments, and varied patterns; (3) Accuracy pass—scan for agreement, articles, prepositions, and word forms. Read aloud to detect awkward rhythm or missing conjunctions. Finally, do a targeted sweep using your personal error log (e.g., singular/plural, “the,” “at/on/in,” “-ly” adverbs). Train yourself to find your top five mistakes first.

How do I choose between similar word forms (noun, verb, adjective, adverb)?

Match the form to the grammatical slot. After modals and auxiliaries, use the base verb (“should increase,” not “should increasing”). Before a noun, use an adjective (“economic growth”), and before an adjective or verb, use an adverb (“significantly higher,” “rapidly increased”). Build families: develop (v), development (n), developing/ developed (adj), developmentally (adv). When editing, highlight endings (“-tion,” “-ment,” “-ly”) to verify the form fits the slot.

How can I avoid awkward or misplaced modifiers?

Place modifiers next to the word they describe: “Students can improve their grammar skills quickly,” not “improve quickly grammar skills.” Avoid dangling participles: “After reviewing the data, the committee revised the policy” (the committee reviewed), not “After reviewing the data, the policy was revised.” If the modifier has room to float, anchor it with a clear subject or rewrite into a clause (“Because the data were limited, the committee adopted a cautious approach”).

Are uncountable nouns a common problem?

Yes. Words like “advice,” “information,” “research,” “equipment,” “progress,” and “furniture” are uncountable and do not take plural “-s” or “many.” Use “much,” “little,” or quantifiers like “a piece of,” “an item of,” “a body of.” Correct: “much research,” “a piece of advice,” “little information.” When you need a countable alternative, choose a different noun: “studies” (countable) instead of “researches.”

What sentence types should I balance for Band 7+?

Mix simple sentences for clarity, compound sentences for coordination of equal ideas, and complex sentences to show subordination and nuance. Example blend: “Public transport is affordable. However, many commuters still prefer cars, and congestion worsens. Although subsidies reduce fares, reliability remains the decisive factor.” This blend demonstrates control, cohesion, and variety without forcing overly long structures.

How do cohesion devices affect perceived grammar quality?

Cohesive devices (moreover, however, therefore, in addition, consequently, for instance) link ideas and guide readers through your logic. Overuse or mechanical stacking (“Firstly, secondly, thirdly” in every paragraph) can sound formulaic. Use them purposefully and vary positions: front (“However, …”), mid-clause (“… is, however, limited”), or clause-initial in the second half of a sentence (“…, and therefore governments should…”). Correct punctuation around these adverbs matters for sentence boundaries.

What practice routine will steadily raise my grammar band?

• Daily 10-minute drill: one grammar micro-skill (articles, prepositions, clauses) with 5–10 targeted items.
• Weekly timed task: write one Task 1 and one Task 2 under exam timing, then self-edit with your checklist.
• Error log update: record the error, the corrected version, the rule, and one fresh example you write yourself.
• Model mimic: rewrite a model paragraph, then paraphrase it with different grammar (e.g., active → passive, simple → complex).

Can strong vocabulary compensate for grammar mistakes?

Rich vocabulary helps with Task Response and Lexical Resource, but it cannot fully offset frequent grammatical errors. In fact, ambitious vocabulary can introduce new mistakes (wrong form, incorrect collocation). Aim for precise, natural words used with correct grammar. Examiners reward clarity over ornamentation.

What last-minute checks should I do in the exam?

• Agreement: underline subjects; tick verbs; confirm singular/plural match.
• Articles: scan nouns for “a/an,” “the,” or zero article—fix the obvious ones.
• Sentence boundaries: split any overly long sentence into two if unsure.
• Prepositions and word forms: spot frequent collocations and “-ly” adverbs.
• Tense timeline: ensure one main time frame per paragraph unless clearly signposted.

Sample corrections: what do typical fixes look like?

Before: “Many people believes that the technology bring many advantages for the society.”
After: “Many people believe that technology brings many advantages for society.”

Before: “Because public transport is cheaper, many commuters use it more, the traffic is reduced.”
After: “Because public transport is cheaper, many commuters use it more, and traffic is reduced.” or “Public transport is cheaper; therefore, many commuters use it more, reducing traffic.”

Before: “We discussed about the problem in the meeting.”
After: “We discussed the problem in the meeting.”

Final takeaway: what mindset leads to fewer errors?

Write with purpose, not performance. Choose structures you can control, then expand gradually. Prioritize clarity, maintain consistent time frames, and edit with a targeted checklist. Over time, a disciplined cycle of writing, reviewing, logging, and re-writing will convert common mistakes into reliable strengths—exactly what the IELTS band descriptors reward.

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