Key Takeaways:
- A handful of error types, led by articles, subject-verb agreement, tense, and prepositions, cause most grammar problems for ESL researchers writing research papers, dissertations, or journal articles.
- The same mistake can distort meaning differently in social science, physical science, and biomedical writing.
- Most errors are fixable with clear rules, a focused review, and an automated grammar check.
- For high-stakes papers, professional editing and proofreading offer the most reliable safeguard.
Glossary of Key Terms
| Term | Definition |
| Article | A word (a, an, the) that signals whether a noun is general or specific. |
| Subject-verb agreement | Matching a verb’s form to a singular or plural subject. |
| Tense | The verb form that signals when an action happens. |
| Preposition | A linking word (in, on, at, with) that connects nouns to other sentence parts. |
| Countable noun | A noun that can take a plural form and a number. |
| Uncountable noun | A noun treated as a mass, without a plural, such as data or evidence. |
| Comma splice | Joining 2 independent clauses with only a comma. |
| Passive voice | A construction in which the subject receives the action. |
| Redundancy | Repeating meaning with unnecessary extra words. |
| ESL | English as a second language. |
Grammar mistakes are easy to make and easy to fix once you know the patterns. For researchers writing in a second language, a small set of error types accounts for most problems in academic writing. This guide covers the 8 most common mistakes, with examples from the social sciences, physical sciences, and biomedical sciences, plus practical ways to catch and correct them.
Why Do Grammar Mistakes Matter for ESL Researchers?
They matter because grammar errors distract reviewers, blur your meaning, and can trigger rejection, even when the underlying science is strong.
From a research proposal to a final manuscript, clear language helps readers follow your research objective and trust your results. Reviewers often read careless grammar as a sign of careless science.
- Errors slow reviewers and weaken first impressions.
- Ambiguity can change how readers interpret your findings.
- Language issues are a common reason for desk rejection.
The same error can read very differently by field. A missing article may look minor in a short physical sciences note, yet the same slip can obscure a key variable in a dense social science argument.
For many ESL researchers, a professional English editing service is the most reliable safeguard against these problems.
See also: 5 Best Online Proofreading Services for Students and Researchers
Which Grammar Mistakes Are Most Common?
The most common mistakes cluster around articles, subject-verb agreement, verb tense, prepositions, countable nouns, comma splices, passive voice, and wordiness. Each section below shows the error and its fix across 3 disciplines.
The grammar rule stays the same across fields, but the vocabulary and the cost of ambiguity differ. Seeing each fix in a familiar context makes the pattern easier to remember and apply in your own drafts.
How Do You Use Articles (a, an, the) Correctly?
Use “a” or “an” for a general or first-mentioned noun and the for a specific one; missing or misused articles are a top error in article usage for non-native writers.
| Discipline | Incorrect | Corrected |
| Social sciences | Researcher administered survey to 200 students. | The researcher administered a survey to 200 students. |
| Physical sciences | We measured velocity of particle. | We measured the velocity of the particle. |
| Biomedical sciences | Patient received placebo for 6 weeks. | The patient received a placebo for 6 weeks. |
A quick check: if a noun is countable, singular, and new to the reader, it almost always needs a or an. If you and the reader already know which specific item you mean, use the.
Why Is Subject-Verb Agreement Easy to Get Wrong?
In subject-verb agreement, the verb must match a singular or plural subject; long noun phrases often trick writers into matching the nearest word rather than the true subject.
| Discipline | Incorrect | Corrected |
| Social sciences | The results of the survey shows a clear trend. | The results of the survey show a clear trend. |
| Physical sciences | The set of equations describe the motion. | The set of equations describes the motion. |
| Biomedical sciences | The prevalence of infections have increased. | The prevalence of infections has increased. |
Which Verb Tense Should You Use?
Use past tense for completed methods and specific results, and present tense for established facts and conclusions; mixing tenses within a section is a frequent slip.
| Discipline | Incorrect | Corrected |
| Social sciences | The 2019 survey shows that inequality rose. | The 2019 survey showed that inequality rose. |
| Physical sciences | We find that the sample expands when we heated it. | We found that the sample expanded when we heated it. |
| Biomedical sciences | The trial demonstrates the drug reduces mortality. | The trial demonstrated that the drug reduced mortality. |
See also: 6 Best Scientific Editing Services for Researchers
Preposition Errors
Errors with prepositions happen when a verb or adjective pairs with the wrong word, such as consistent to instead of consistent with; these collocations must be learned individually.
| Discipline | Incorrect | Corrected |
| Social sciences | The findings are consistent to prior research. | The findings are consistent with prior research. |
| Physical sciences | Pressure was recorded in 25 degrees Celsius. | Pressure was recorded at 25 degrees Celsius. |
| Biomedical sciences | Patients were diagnosed of diabetes. | Patients were diagnosed with diabetes. |
Countable vs Uncountable Noun Mistakes
Words such as data, evidence, research, and equipment are uncountable nouns in academic English, so they take no plural s and pair with much, not many.
| Discipline | Incorrect | Corrected |
| Social sciences | The interviews produced many evidences. | The interviews produced substantial evidence. |
| Physical sciences | We used several equipments in the lab. | We used several pieces of equipment in the lab. |
| Biomedical sciences | Recent researches confirm the link. | Recent research confirms the link. |
What Is a Comma Splice, and How Do You Fix It?
A comma splice joins 2 complete sentences with only a comma; fix it with a semicolon, a period, or a coordinating conjunction such as and or so.
| Discipline | Incorrect | Corrected |
| Social sciences | The sample was small, the results are inconclusive. | The sample was small; the results are inconclusive. |
| Physical sciences | The reaction was exothermic, the temperature rose. | The reaction was exothermic, so the temperature rose. |
| Biomedical sciences | The dose was increased, adverse effects appeared. | The dose was increased, and adverse effects appeared. |
Is Passive Voice Always Wrong?
No: passive voice is acceptable, but overusing agentless passives buries who did what; prefer active voice when the actor matters, and reserve passive for routine methods.
| Discipline | Incorrect | Corrected |
| Social sciences | It was found by the researchers that trust declined. | The researchers found that trust declined. |
| Physical sciences | The data were analyzed by us using regression. | We analyzed the data using regression. |
| Biomedical sciences | The samples were collected and were labeled by nurses. | Nurses collected and labeled the samples. |
Discipline norms vary. Methods sections in the physical and biomedical sciences often accept passive constructions, while many social science journals now encourage active voice and first person. Match your target journal’s style.
Wordiness and Redundancy
Cutting wordiness and redundancy replaces empty phrases like due to the fact that with because, and removes words that repeat meaning already present in the sentence.
| Discipline | Incorrect | Corrected |
| Social sciences | Due to the fact that respondents were absent, data were lost. | Because respondents were absent, data were lost. |
| Physical sciences | In order to be able to measure the exact value, we calibrated. | To measure the exact value, we calibrated. |
| Biomedical sciences | Patients exhibited symptoms that were severe in nature. | Patients had severe symptoms. |
Concise writing is not only cleaner; it also lowers your word count, which helps when journals set strict limits on abstracts and articles.
What Other Mechanics Issues Should You Watch?
Beyond the top 8, watch punctuation, capitalization, and discipline-specific conventions, since small slips in these areas still distract reviewers and readers.
- Apostrophe and quotation mark use in possessives and quotations.
- Semicolon and colon rules for linking related clauses.
- Capitals and abbreviations, with each abbreviation defined on first use.
- Hyphen, en dash, and em dash distinctions in ranges and compounds.
- Conjunctions and modal verbs for logic and careful hedging.
- Scientific names written with correct binomial nomenclature.
- Numbers and units formatted to your journal’s style.
- Terminology precision and commonly confused words.
- British vs American English kept consistent throughout.
- Reporting verbs and varied sentence structure.
- First person vs third person used consistently.
These surface details are exactly what a proofreading service is designed to catch before you submit.
How Can You Catch and Fix These Mistakes?
Combine self-editing habits, an automated checker, and professional help: read aloud, check 1 error type at a time, and run a grammar tool before a human review.
- Review 1 error type per pass, starting with articles and verbs.
- Read sentences aloud to hear awkward phrasing and missing words.
- Keep a personal list of errors you repeat, and search for them.
- Check tables, figures, and references separately from the main text.
A tool such as Paperpal flags many of these errors instantly, which makes your first pass faster and more thorough.
| Option | Best for | Keep in mind |
| Grammar tool | Fast first-pass checks | Misses nuance and context |
| Professional editing | Grammar, clarity, terminology | Deeper investment |
| Professional proofreading | Error-free final file | Assumes content is settled |
For quick self-checks, Paperpal reviews grammar and style in seconds. For expert help, an English editing service corrects language and terminology, while a proofreading service delivers a clean final draft.
Whether you are drafting your first paper or revising a resubmission, professional English editing helps your research read as clearly as it deserves to.
See also: What are parts of speech? Nouns, verbs, adjectives, and more
Frequently Asked Questions
What are the most common grammar mistakes in academic writing?
The most frequent errors involve articles, subject-verb agreement, verb tense, prepositions, countable nouns, comma splices, passive voice, and wordiness. These 8 account for a large share of language problems in research papers.
Why do non-native English speakers struggle with articles in research papers?
Many first languages have no direct equivalent of a, an, or the, so the rules feel unfamiliar. Writers then drop articles or overuse the, which reviewers notice quickly. Focused practice and editing help.
What tense should I use in a research paper?
Use past tense for your completed methods and specific results, and present tense for established facts and your conclusions. Keep tenses consistent within each section to avoid confusing readers.
Is passive voice wrong in scientific writing?
No. Passive voice is standard for describing methods and is accepted in most journals. The problem is overuse, which hides the actor and adds words. Use active voice when the doer matters.
How can I improve my grammar for academic writing?
Read widely in your field, learn the error types you repeat, and review 1 issue at a time. Combine an automated grammar checker with professional editing for the most consistent results.
Do grammar checkers fix all academic writing errors?
No. Grammar checkers catch many surface errors quickly, but they miss nuance, discipline-specific terminology, and argument-level issues. They work best as a first pass before human editing and proofreading.
Should I write data is or data are in a research paper?
Treat data as plural in formal academic writing, so use data are. Data is appears in casual usage, but most journals and style guides still prefer the plural form for research papers.
What is a comma splice, and how do I fix it?
A comma splice joins 2 complete sentences with only a comma. Fix it by using a period, a semicolon, or a coordinating conjunction such as and, but, or so between the clauses.
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