Ever submitted a paper that felt brilliant only to lose points over grammar? It’s frustrating. You had the ideas, the research, the evidence. Yet a few missing commas or awkward verb choices made your work look less polished than it deserved. Academic writing isn’t just about what you say; it’s about how clearly and correctly you say it.
Here’s what matters: grammar is not about perfection it’s about clarity. The moment grammar slips, meaning bends. And when meaning bends, your credibility takes the hit. Let’s fix that by walking through the most common grammatical mistakes in academic writing and how to avoid them without sounding like a robot.
Understanding Why Grammar Matters in Academic Writing
Academic writing aims to communicate complex ideas in the simplest possible way. Readers professors, peers, or reviewers don’t want to decode your sentences; they want to understand your argument. That’s where grammar steps in as your invisible assistant.
Poor grammar distracts. It makes readers pause, reread, and doubt the quality of your thinking. When you write clearly, you’re not just showing that you understand your topic you’re showing that you respect your reader’s time.
As the University of Georgia’s writing guide reminds students, “grammar mistakes signal carelessness, even when your ideas are strong.” A small slip like using “its” instead of “it’s” can weaken the authority of your entire paragraph.
The Most Common Grammatical Mistakes in Academic Writing
You’ll find hundreds of lists titled “100 common mistakes in English,” but in real academic writing, only a few patterns keep showing up. Let’s unpack them each with examples and quick fixes.
1. Subject-Verb Agreement Errors
Every sentence needs a subject and a verb that agree in number. If the subject is singular, the verb must be singular too. This sounds easy, but complex sentences make it tricky.
Wrong:
The list of topics are too long.
Correct:
The list of topics is too long.
The confusion happens because writers focus on the word “topics,” not “list.” Remember: the subject here is “list,” which is singular.
Quick fix:
After writing a sentence, isolate the subject and verb. Ask: Who or what is doing the action? Then check if both are singular or plural.
2. Misusing Commas
Commas can be your best friend or your biggest problem. In academic writing, too many commas break flow; too few cause confusion.
Common issues:
- Missing commas after introductory phrases
- Using commas between two complete sentences (comma splice)
Wrong:
However I believe this theory is outdated.
Correct:
However, I believe this theory is outdated.
Wrong:
The study was detailed, it provided several key insights.
Correct:
The study was detailed, and it provided several key insights.
Quick fix:
Read your sentence aloud. If you naturally pause, a comma may belong there. If you can replace a comma with a period and both sides still make sense, you probably need a conjunction instead.
3. Sentence Fragments and Run-Ons
In an effort to sound academic, some writers stretch their sentences endlessly or cut them too short. Both hurt readability.
Fragment example:
Because the results were inconclusive.
That’s not a full sentence. It leaves the reader waiting for the main clause.
Correct:
Because the results were inconclusive, the researchers extended the study.
Run-on example:
The experiment failed it was conducted under poor conditions.
Correct:
The experiment failed because it was conducted under poor conditions.
Quick fix:
Each sentence must contain one complete thought: subject + verb + meaning that stands alone. If it doesn’t, join it or expand it.
4. Misplaced Modifiers
Modifiers describe or add detail but if they’re in the wrong place, they create comedy instead of clarity.
Wrong:
Students who failed the exam were told to study harder by the professor.
Did the professor fail the exam? Probably not.
Correct:
The professor told students who failed the exam to study harder.
Quick fix:
Place modifiers as close as possible to the word they describe.
5. Confusing Homophones
Some words sound the same but mean entirely different things. In academic writing, these tiny mix-ups can look careless.
Common offenders:
- Their / There / They’re
- Its / It’s
- Affect / Effect
- Then / Than
Example:
The new method had a greater affect on results. ❌
The new method had a greater effect on results. ✅
Quick fix:
If in doubt, check meaning not sound. Even advanced writers benefit from keeping a quick homophone list nearby.
6. Overusing Passive Voice
Academic writing often favors objectivity, so the passive voice can seem tempting. But overuse makes your writing dull and indirect.
Example:
Passive: The experiment was conducted by the team.
Active: The team conducted the experiment.
Both are correct, but the active version is stronger and shorter.
Quick fix:
Use passive voice when the doer is unknown or irrelevant (e.g., “The samples were tested at room temperature”). Otherwise, keep it active.
7. Inconsistent Verb Tense
Mixing tenses within a paragraph confuses readers and distorts the timeline of your argument.
Wrong:
The researcher examines the data and concluded that it was valid.
Correct:
The researcher examined the data and concluded that it was valid.
Quick fix:
Pick a tense based on your paper’s context past for completed research, present for general truths and stick to it.
8. Redundancy and Wordiness
Academia sometimes rewards complexity, but clarity wins every time. Repeating words or padding sentences with unnecessary phrases makes your writing feel heavy.
Wordy:
Due to the fact that the study was limited in nature, further research is absolutely necessary.
Tightened:
Because the study was limited, further research is necessary.
Quick fix:
After writing, delete 10% of your words. If your sentence keeps its meaning, you’ve made it stronger.
9. Incorrect Use of Apostrophes
Possession and contraction are where most writers slip.
Common confusion:
- Student’s = one student’s possession
- Students’ = multiple students’ possession
- Students = plural, no possession
Example:
The students’ feedback improved the course. ✅
Quick fix:
If you can replace it with “of,” it likely needs an apostrophe.
10. Using “This” or “It” Without a Clear Reference
Every pronoun should clearly refer to a noun. In long academic paragraphs, pronouns like “this,” “that,” or “it” often lose their subject.
Vague:
This is significant because it proves the point.
Clear:
This finding is significant because it proves the point.
Quick fix:
After “this” or “it,” name what you’re referring to, at least once per paragraph.
Examples from Real Academic Writing
Let’s look at one polished example rewritten from a typical student paper.
Before:
There is a large amount of evidence which suggest that students perform better when they are learning in environments that are quiet and peaceful because it allows concentration and helps in focus.
After:
A large amount of evidence suggests that students perform better in quiet, peaceful environments, which support concentration and focus.
What changed:
- Corrected “suggest” to “suggests” (subject-verb agreement)
- Removed “there is” (redundant)
- Tightened phrasing (“helps in focus” → “support concentration and focus”)
This small clean-up improved rhythm, clarity, and academic tone all without adding complexity.
How to Avoid Grammar Mistakes Before Submission
Let’s face it: even strong writers make errors when tired, rushed, or too close to their work. The key is to build a system that catches mistakes before your professor does.
Here’s a proven workflow:
- Take a break before editing. Step away for at least 20 minutes after writing. You’ll spot errors you missed earlier.
- Read aloud. Your ears catch rhythm problems that your eyes ignore.
- Use digital tools wisely. Grammarly, ProWritingAid, or even ChatGPT can help but don’t rely blindly. Machines catch surface issues, not nuance.
- Check one issue at a time. Do one pass for punctuation, one for verb tense, one for structure.
- Use peer review. A second reader spots gaps in logic and unclear pronouns.
- Create a personal error list. Note the mistakes you repeat. Over time, you’ll train yourself out of them.
Applying AI to Improve Grammar (Without Losing Your Voice)
As someone who spends a lot of time around AI writing tools, I’ve learned one truth: they’re only as good as their human operator. Tools like ChatGPT, Grammarly, and Quillbot can identify patterns of mistakes but they can’t feel your intent.
Here’s how to use them well:
- Let AI suggest corrections, but review every change manually.
- Use style feedback to learn not to erase your tone.
- Run your work through grammar tools early, not at the end. It saves hours of rewrites.
Think of AI as your digital proofreader, not your ghostwriter.
Building Grammar Awareness Long-Term
Avoiding grammar mistakes isn’t a one-time fix; it’s a mindset. You build awareness by reading better writing and practicing mindful editing.
Here’s what works long-term:
- Read published academic papers and notice sentence structure.
- Rewrite paragraphs from professional sources using simpler words.
- Keep a “grammar wins” journal where you note improvements.
- Reward clarity, not complexity.
You’ll find that strong grammar grows from habits, not rules.
Final Thoughts
Avoiding common grammatical mistakes in academic writing isn’t about memorizing 100 rules it’s about writing with intention. When you respect the sentence, you respect your reader. When you write clearly, you make your thinking visible.
The best writers aren’t the ones who never make errors; they’re the ones who notice and fix them early. So the next time you draft a paper, think of grammar not as a hurdle, but as a tool one that helps your ideas stand tall and your reader stay with you from start to finish.
Bottom line: clarity is your credibility.
AI writing strategist with hands-on NLP experience, Liam simplifies complex topics into bite-sized brilliance. Trusted by thousands for actionable, future-forward content you can rely on.