Writing a research manuscript is never just about the research: it’s also about communicating the research clearly. But many authors (especially non-native English speakers) let avoidable grammar mistakes undermine their paper. Here are ten of the most common grammar problems in research papers—and practical fixes you can apply.
Ten Common Grammar Problems
Subject-Verb Agreement
One of the most basic errors: the verb doesn’t agree in number (singular/plural) with its subject. For example: “The results of the experiment shows …” should be “The results … show …”. (Ref-N-Write)
Fix: After writing a sentence, isolate subject + verb and check: is my subject singular? Then use a singular verb (e.g., “is” not “are”). If plural, use plural verb.
Incorrect or Missing Articles (“a”, “an”, “the”)
Researchers often mix up articles, omit them, or use “the” when it’s not needed. As one source explains: “Accurate article usage is extremely important for clarity and readability.” (Editage)
Fix: If a noun is singular and countable and this is its first mention → use “a”/“an”. If it’s specific and already known → use “the”. If you’re talking in general terms about an abstract concept or discipline, often no article is needed.
Parallelism and Inconsistent Structure
This error shows up when list items or paired clauses are not written in the same grammatical structure. Example given by Editage: “Tina likes reading, painting, and to cook.” instead of “reading and cooking” or “to read, to paint, and to cook.” (Editage)
Fix: When you have a list or series (verbs, nouns, phrases), make sure each element uses the same form. Read the list aloud to check consistency.
Misuse of Relative Pronouns (“that” vs. “which/who”)
Academic writing often needs precision. One common mistake: misusing “which” and “that”. As one Editage article states: “Essential information used to define a noun should be preceded by ‘that’, whereas ‘which/who’ precedes additional information that is not necessary to define the noun.” (Editage)
Fix: If the clause defines the noun (identifies only which one) → use “that” (no comma). If it’s extra information (non-defining) → use “which/who” + comma.
Word Choice Errors (Wrong Form, Confusing Words)
Non-native authors often pick a word that sounds similar but doesn’t quite fit, or pick a form of a word that muddles meaning. (Editage)
Fix: Whenever you use a verb/noun/adjective form you’re not 100% sure of, verify its meaning in a trusted academic dictionary. Consider: does the meaning fit exactly? Is there a simpler word that suffices?
Run-On Sentences / Sentence Fragments
Either you cram too many clauses into one long sentence (making it confusing) or you leave a sentence incomplete (fragment). For example: “The theory was widely accepted it lacked empirical support.” (run-on) (Ref-N-Write)
Fix: Break long sentences at logical points; use conjunctions or appropriate punctuation. Or if fragment, check: does the sentence have a subject + verb + complete thought?
Misplaced or Dangling Modifiers
If a modifier (phrase or clause) is placed poorly, it may unintentionally attach to the wrong word. The general “common writing errors” list from OWL includes this. (Excelsior OWL)
Fix: After writing a phrase like “Having conducted the experiment, …”, check: is the subject of the main clause the person who “conducted the experiment”? If not, rephrase to attach correctly.
Over-use of Nominalization
Nominalization means turning verbs or actions into nouns (often making sentences heavier). Editage identifies this for research writing: e.g., instead of “We had a discussion about the issue.”, write “We discussed the issue.” (Editage)
Fix: Whenever you see long phrases like “the implementation of the method”, ask: could I say “we implemented the method”? Active, verb-based forms are often clearer.
Inconsistent or Incorrect Tense Usage
In research writing, you need consistency: e.g., past tense for what you did, present tense for accepted knowledge. Editage’s series points this out (in “6 mistakes” Part 2). (Editage)
Fix: Decide: For your methods/results → past tense (we evaluated, we observed). For general statements, accepted knowledge → present tense (X is known). Then scan for any mismatch and correct.
Punctuation and Comma Errors (Introductory commas, lists, etc)
Missing commas (such as after an introductory phrase) or incorrect use (in lists, complex sentences) are frequent. For example: “In this study we were unable …” should be “In this study, we were unable …”. (Editage)
Fix: After any introductory adverbial phrase (e.g., “In this study”, “However”, “Therefore”), insert a comma. For lists, check consistency and clarity. Read the sentence aloud: if you naturally pause, consider a comma.
Why Fixing These Matters
While your findings may be novel and your data sound, grammar mistakes can distract reviewers and editors. Simple English grammar mistakes or proofreading errors can detract from the overall quality of your paper.
Beyond credibility, clear writing helps your audience (other researchers) focus on your science, not your grammar. It also reduces risk of misinterpretation of key points.
Quick Checklist for Manuscript Polishing
- Use a grammar-checker or have a trusted peer proofread (especially non-native speakers).
- Print out your manuscript and read sentence by sentence (or read aloud) to catch awkward phrasing or missing punctuation.
- Focus on the 10 areas above: subject-verb agreement, articles, parallel structure, word choice, tense, modifiers, nominalization, run-ons/fragments, relative pronouns, punctuation.
- Ensure consistency in style (e.g., British vs American English spelling) and follow your target journal’s guidelines.
- Consider having an editor familiar with academic English review your final draft—don’t assume your word-processor will catch everything.
Final Thoughts
Asking the prompt “What are the most common grammar mistakes in papers?” can help you self-audit your draft. Use it as a lens: go through your manuscript and ask for each section: “Am I making any of these ten errors?” With some conscious effort and proofreading, you can transform your manuscript from good science + shaky grammar into good science + crisp writing. That difference matters.
Best of luck with your writing — and may your next submission sail through review with fewer corrections!
