Why does a supervisor return a chapter full of red marks when the ideas are sound? Usually because the same few patterns repeat on every page. Academic English grammar mistakes made by non-native writers are remarkably consistent: articles, uncountable nouns, tense choice, verb patterns and sentence boundaries account for most of them. This guide groups 25 errors into five families, gives a wrong and a corrected sentence for each, and ends with a method for finding them in your own draft. Spelling follows British conventions.
This article is part of our guide How to Write a Master’s Thesis by the Mastermind PhD team and relates to our Academic Proofreading & Review service. Sources last checked: November 2026.
What counts as a grammar error in academic writing? A grammar error is a form that breaks the rules of standard written English, such as a missing article, a wrong verb form or a subject and verb that do not agree. It differs from a style issue (an informal word or an over-long sentence), which is grammatically correct but unsuitable for academic prose. Examiners tolerate occasional slips, but repeated errors can obscure meaning and lower the mark for presentation.
Which article and noun errors are most common?
Articles (a, an, the) do not exist, or work differently, in many languages, including Arabic, Chinese, Russian and Turkish. They are usually the largest single source of academic English grammar mistakes.
| # | Error | Wrong | Correct |
|---|---|---|---|
| 1 | “The” with general plural or uncountable nouns | The education is a key to development. | Education is a key to development. |
| 2 | Missing article with a singular countable noun | This is important factor. | This is an important factor. |
| 3 | Plural forms of uncountable nouns | Many researches provide evidences. | Much research provides evidence. / Many studies provide evidence. |
| 4 | Wrong agreement with “data” | The data shows… (in a field that treats data as plural) | The data show… |
| 5 | Agreement with a long subject | The results of the analysis shows… | The results of the analysis show… |
| 6 | “One of the” with a singular noun | One of the main reason is… | One of the main reasons is… |
Other nouns that are normally uncountable in academic English include information, knowledge, feedback, equipment and advice. Check your field’s convention for “data”: APA style treats it as plural, while many science and computing texts accept the singular.
Which verb and tense errors appear in every chapter?
| # | Error | Wrong | Correct |
|---|---|---|---|
| 7 | Present perfect with a specific past study | Smith (2019) has found that… | Smith (2019) found that… |
| 8 | Present tense for your own results | The mean score is higher in group A. | The mean score was higher in group A. |
| 9 | Wrong participle in the passive | The questionnaire was distribute to 300 teachers. | The questionnaire was distributed to 300 teachers. |
| 10 | Dangling modifier | Using SPSS, the data were analysed. | The data were analysed using SPSS. |
| 11 | Wrong verb pattern | This allows to compare groups. / We suggest to use… | This allows researchers to compare groups. / We suggest using… |
Error 10 is subtle: the opening phrase “Using SPSS” must describe the subject of the main clause, and data cannot use software. Errors 7 and 8 are about tense choice per chapter, which our guide to academic style covers in detail.
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Which preposition errors should you check?
Preposition errors rarely block meaning, but they are among the academic English grammar mistakes that examiners notice most quickly because they repeat.
| # | Error | Wrong | Correct |
|---|---|---|---|
| 12 | Unnecessary preposition after a transitive verb | We discuss about the results. / The study emphasises on… | We discuss the results. / The study emphasises… |
| 13 | Wrong preposition | depend of, consist from, responsible of | depend on, consist of, responsible for |
| 14 | “Despite of” | Despite of the small sample… | Despite the small sample… / In spite of the small sample… |
| 15 | “Comparing to” for a comparison | Comparing to previous studies, our results… | Compared with previous studies, our results… |
A learner’s dictionary such as the Oxford Advanced Learner’s Dictionary or Cambridge Dictionary lists the prepositions each verb, noun and adjective takes; check there rather than translating from your first language.
Which sentence structure errors weaken an argument?
| # | Error | Wrong | Correct |
|---|---|---|---|
| 16 | Comma splice | The sample was small, the results cannot be generalised. | The sample was small, so the results cannot be generalised. |
| 17 | Sentence fragment | Because the sample was small. | Because the sample was small, the results cannot be generalised. |
| 18 | Double connector | Although the effect was small, but it was significant. | Although the effect was small, it was significant. |
| 19 | Question word order in an indirect question | This study investigates what are the factors. | This study investigates what the factors are. |
| 20 | “Also” at the start of a sentence | Also, the sample was limited to one city. | In addition, the sample was limited to one city. |
Among academic English grammar mistakes, errors 16 to 18 are especially common among writers whose first language links clauses with commas or uses paired connectors such as “although… but”. In English, “although” and “but” do not appear together in the same sentence.
Which word choice errors look like grammar errors?
| # | Error | Wrong | Correct |
|---|---|---|---|
| 21 | Affect versus effect | Stress effects performance. | Stress affects performance. (verb) / Stress has an effect on performance. (noun) |
| 22 | Fewer versus less | less participants | fewer participants (countable) / less time (uncountable) |
| 23 | Wrong verb with “research” | We made a research on… | We conducted research on… / We carried out a study of… |
| 24 | i.e. versus e.g. | several tests, i.e. t-tests and ANOVA (when the list is incomplete) | several tests, e.g. t-tests and ANOVA |
| 25 | Vague “this” or “it” | This shows that… (after a long paragraph) | This difference shows that… |
Several of these look like vocabulary problems, yet supervisors list them with other academic English grammar mistakes. Item 25 is often treated as a style issue, but an unclear pronoun can make a sentence ambiguous, which is why many supervisors mark it.
How do you find academic English grammar mistakes in your own draft?
Reading a whole chapter “for grammar” rarely works; your eye corrects what it expects to see. A targeted method finds far more academic English grammar mistakes:
- Search for patterns. Use Word’s Find function for “researches”, “informations”, “evidences”, “discuss about”, “despite of”, “although” and “comparing to”. Each hit takes seconds to check.
- Read one family at a time. On one pass, check only articles before nouns; on the next, only verbs in the results chapter.
- Read aloud or use text-to-speech. Fragments and comma splices are easier to hear than to see.
- Keep a personal error log. Note every correction your supervisor makes. Most writers have five to ten personal patterns, and the log turns them into a checklist.
- Use tools carefully. Spelling and grammar checkers catch some agreement and spelling errors but miss many article errors, and their rewriting suggestions can change your meaning. Check your university’s rules before using AI-based editors on assessed work.
Should you hire a proofreader or fix the errors yourself?
Both are legitimate if they stay within your university’s rules. Many UK universities allow a proofreader to correct grammar, spelling and punctuation but not to rewrite content or arguments, and some require you to declare the help. A proofreader’s corrections are also a learning resource: if you study why each change was made, the same academic English grammar mistakes stop appearing in the next chapter. Our article on proofreading rules at UK universities summarises what is usually permitted.
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Frequently asked questions
Which grammar error is most common for non-native writers?
Of all academic English grammar mistakes, article errors are usually the most frequent, especially for writers whose first language has no articles. Errors with uncountable nouns such as research, evidence and information come close behind.
Is “data” singular or plural?
Both uses exist. APA style and many social science journals treat “data” as plural (the data show), while some fields accept the singular. Choose one and use it consistently.
Do grammar mistakes lower my thesis mark?
Occasional slips rarely matter. Frequent errors that obscure meaning can affect marks for presentation and clarity, and examiners may require corrections before the final version is accepted.
Are grammar checkers reliable for academic writing?
Partly. They catch many agreement and spelling errors but miss or mishandle many article and word choice errors, and some features rewrite text in ways your university may not permit.
Should I use British or American spelling?
Use the one your university or target journal expects, and stay consistent. In Word, set the language for the whole document so the spell checker follows the same convention.
Sources
- Swan, M. (2016). Practical English Usage (4th ed.). Oxford University Press.
- Swales, J. M., & Feak, C. B. (2012). Academic Writing for Graduate Students: Essential Tasks and Skills (3rd ed.). University of Michigan Press.
- Morley, J. Academic Phrasebank. The University of Manchester. https://www.phrasebank.manchester.ac.uk/ (accessed November 2026)
- American Psychological Association. (2020). Publication Manual of the American Psychological Association (7th ed.). https://doi.org/10.1037/0000165-000
- University of Birmingham, Library Services. Using Grammarly responsibly within your academic work. https://intranet.birmingham.ac.uk/student/libraries/asc/grammarly.aspx (accessed November 2026)
Sources last checked: November 2026. This article is general educational guidance and does not replace your university regulations or your supervisor’s instructions. How we prepare our content.