Do your supervisor’s comments keep returning to the same small problems: a missing “the”, a tense that changes mid-paragraph, a sentence that runs for five lines? For anyone writing a thesis in English as a second language, these errors are normal and fixable. They rarely come from weak English overall; they come from patterns carried over from the first language and from the special demands of academic register.
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.
This guide lists 20 errors that commonly appear in a thesis in English written by second-language writers, grouped into six areas, each with an example and a correction. It ends with a routine for finding them in your own text before your supervisor does.
What is a second-language thesis error? It is a recurring deviation from standard academic English that reflects the writer’s first language or unfamiliarity with academic conventions, such as article use, tense choice, word collocation or sentence length. Individually small, these errors reduce clarity and credibility when they are repeated throughout a long document.
Articles and nouns (errors 1 to 4)
Articles are the most frequent problem in a thesis in English written by speakers of languages that have no articles or use them differently.
- Missing “the” with specific reference. Incorrect: “Results of study show…” Correct: “The results of the study show…”
- “The” with general plural or uncountable nouns. Incorrect: “The education is important for the development.” Correct: “Education is important for development.”
- Countable versus uncountable nouns. “Research”, “information”, “evidence”, “knowledge” and “feedback” are uncountable in standard usage. Write “studies” or “pieces of evidence”, not “researches” or “evidences”.
- Singular count noun with no article. Incorrect: “We used questionnaire to collect data.” Correct: “We used a questionnaire to collect data.”
A quick test for articles: for each singular countable noun, ask whether the reader knows which one you mean. If yes, use “the”; if it is one of many, use “a” or “an”; if the noun is plural or uncountable and general, use no article.
Verbs and tenses in a thesis in English (errors 5 to 8)
- Inconsistent tense in the literature review. Choose a convention and keep it: past tense for a specific study (“Smith (2020) found…”), present tense for established knowledge (“Motivation predicts performance”).
- Wrong tense in the method and results. Describe what you did and found in the past tense: “Participants completed the survey”, “The mean score was 3.4”.
- Subject-verb agreement with long subjects. Incorrect: “The effect of these factors on teachers are significant.” Correct: “The effect … is significant.” The verb agrees with “effect”, not with “factors”.
- “Data” agreement. Many style guides, including APA, treat “data” as plural (“the data were collected”). Whichever form your discipline uses, apply it consistently.
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Word choice (errors 9 to 12)
| Error | Incorrect | Better |
|---|---|---|
| 9. False friends and literal translations | “The actual study” (meaning current) | “The present study” |
| 10. Wrong collocations | “make a research”, “do a mistake” | “conduct research”, “make a mistake” |
| 11. Informal vocabulary | “a lot of”, “big”, “get”, “things” | “many”, “substantial”, “obtain”, “factors” |
| 12. Overstatement | “This proves that…” | “These results suggest that…” |
Error 12 matters more than it seems. Academic English hedges claims to match the strength of the evidence; a thesis in English that “proves” everything sounds less credible, not more.
Sentence structure (errors 13 to 16)
- Very long sentences. Sentences of 50 or more words, often built with “and” and “which”, are common when the first language allows long chains. Aim for one main idea per sentence and split at the second “which”.
- Comma splices. Incorrect: “The sample was small, the results cannot be generalised.” Correct: “The sample was small, so the results cannot be generalised.” or use a semicolon.
- Sentence fragments. Incorrect: “Because the response rate was low.” standing alone. Attach the clause to a main clause.
- Dangling modifiers. Incorrect: “Using SPSS, the data showed a significant difference.” Correct: “Using SPSS, we found a significant difference.”
Academic style and cohesion (errors 17 and 18)
- Overused or misused linking words. “Moreover”, “furthermore” and “in addition” at the start of every sentence create a list, not an argument. “On the other hand” requires a first hand; “however” signals contrast, not addition.
- Paragraphs without a topic sentence. Each paragraph should open with its main point and then develop it. Second-language writers often build up to the point at the end, a structure common in some rhetorical traditions but harder to follow in English academic prose.
Punctuation and mechanics (errors 19 and 20)
- Inconsistent spelling convention. Mixing “analyse” and “analyze”, “behaviour” and “behavior” in one document. Choose UK or US spelling according to your university and set the spell checker to that variant.
- Capitalisation and number errors. Capitalising common nouns (“the Students in the Sample”), inconsistent number style (“five” and “5” for the same type of value), and decimal commas instead of decimal points.
How can you find these errors in your own thesis in English?
Self-editing works best when you read for one type of error at a time rather than for everything at once:
- Pass 1, structure: read only the first sentence of each paragraph. Together they should summarise the chapter.
- Pass 2, sentences: mark every sentence longer than about 35 words and decide whether it can be split.
- Pass 3, grammar: search for your personal weak points, such as “the”, “which”, “data” or a tense you often confuse.
- Pass 4, vocabulary: search for “prove”, “a lot”, “thing” and other informal or overstated words.
- Pass 5, mechanics: run the spell checker in the right language variant and check numbers and capitals.
Keep a personal error log from your supervisor’s comments. After two or three chapters, most writers see that a handful of errors account for most corrections, and those become the first things to search for. Reading the text aloud, slowly, also reveals missing words and broken sentences that the eye skips.
Phrase resources such as the University of Manchester’s Academic Phrasebank can help with functional phrases for introducing a gap, describing methods or reporting results. Use them for structure, not as a substitute for your own argument.
Finally, plan time for language revision in your schedule. Revising a thesis in English chapter by chapter, as each one is drafted, is far easier than correcting a hundred pages in the final week, and it means your supervisor can concentrate on the research rather than on grammar.
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Frequently asked questions
Is it acceptable to use a grammar checker?
Usually yes, for spelling and grammar, but check your university’s policy on AI-based tools that rewrite text. Treat suggestions critically: grammar checkers often miss article errors and sometimes introduce new ones.
Should I write in my first language and translate?
Some writers draft ideas in their first language, but translating full chapters tends to produce long sentences and literal phrasing. Writing directly in English, then revising, usually gives a more natural thesis in English.
How much will language errors affect my grade?
It depends on the marking criteria. Most rubrics assess clarity and academic communication; errors that obscure meaning cost more than occasional slips that do not.
Can someone proofread my thesis?
Many universities permit proofreading limited to spelling, grammar and punctuation, and prohibit changes to content or argument. Check the policy and disclose the help you received if required.
Should I use UK or US English?
Use the variant your university or style guide requires. If there is no rule, choose one and apply it consistently, including in quotations you paraphrase.
Sources
- Swales, J. M., & Feak, C. B. (2012). Academic Writing for Graduate Students: Essential Tasks and Skills (3rd ed.). University of Michigan Press.
- Swan, M. (2016). Practical English Usage (4th ed.). Oxford University Press.
- American Psychological Association. (2020). Publication Manual of the American Psychological Association (7th ed.). APA.
- Purdue Online Writing Lab. Using Articles. https://owl.purdue.edu/owl/general_writing/grammar/using_articles.html (accessed November 2026)
- University of Manchester. Academic Phrasebank. https://www.phrasebank.manchester.ac.uk/ (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.