12 Common English Mistakes in Research Papers (and How to Fix Them)

After editing hundreds of thousands of papers, our editors see the same patterns again and again. None of them mean your science is weak — but together they make a paper harder to read and easier to reject. Here are the twelve we correct most, with quick fixes.

1. Missing or incorrect articles

Before: “We measured concentration of protein in sample.”
After: “We measured the concentration of protein in each sample.”
Singular countable nouns almost always need “a”, “an” or “the”.

2. Switching tenses

Use the past tense for what you did and found (“we observed”), and the present tense for established facts and for what your paper shows (“these results suggest”). Keep each section consistent.

3. Sentences that are too long

If a sentence has more than about 30 words or three commas, split it. One idea per sentence is a good rule in Methods and Results.

4. “Which” versus “that”

In American English, “that” introduces essential information without commas; “which” adds extra information after a comma. “The samples that were contaminated were discarded” (only some) vs “The samples, which were contaminated, were discarded” (all).

5. Wrong prepositions

Common examples: “depend on” (not “of”), “consist of”, “different from”, “interested in”, “compared with” for detailed comparisons.

6. Uncountable nouns used as plurals

“Researches”, “informations”, “evidences”, “equipments” and “softwares” are incorrect. Use “studies”, “information”, “evidence”, “equipment”, “software”.

7. Dangling modifiers

Before: “After centrifuging, the supernatant was removed.” (The supernatant didn’t centrifuge.)
After: “After the samples were centrifuged, the supernatant was removed.”

8. Overusing “respectively”

Use “respectively” only when matching two parallel lists: “Groups A and B received 5 and 10 mg, respectively.” Otherwise, rewrite for clarity.

9. Informal words

Replace “a lot of” with “many/much”, “get” with “obtain”, “big” with “large/substantial”, “show up” with “appear”. Avoid contractions such as “don’t”.

10. Too many nouns (nominalisation)

Before: “The performance of an analysis of the data was carried out.”
After: “We analysed the data.” Strong verbs make sentences shorter and clearer.

11. Inconsistent terminology

Choose one term and keep it: don’t alternate between “participants”, “subjects” and “patients”, or between “data set” and “dataset”. Define each abbreviation once, at first use.

12. Over-hedging or over-claiming

“It may possibly be suggested that…” is too weak; “This proves that…” is usually too strong. Prefer “These results suggest…” or “This indicates…”, matched to the strength of your evidence.

How to catch these mistakes yourself

• Read your paper aloud — long sentences and missing words become obvious.
• Search your document for “researches”, “informations” and “respectively”.
• Check each section’s tense in one pass.
• Ask a colleague in a neighbouring field to read the abstract.

Grammar tools help with spelling but miss most of the errors above, especially in technical writing. For a paper you plan to submit, a subject-expert English edit is the safest option. See before-and-after samples.

Frequently asked questions