Grammar & Style

10 Most Common Grammar Mistakes and How to Fix Them

February 06, 2026 · 1 min read · 10 views

Even experienced writers make grammar mistakes. Knowing the most common ones helps you catch and fix them before they reach your audience. Here are the ten most frequent grammar errors and how to correct them.



1. Subject-Verb Agreement


Wrong: "The list of items are on the desk."
Right: "The list of items is on the desk."


The subject "list" is singular, so the verb must be singular too. Don't be misled by prepositional phrases between the subject and verb.



2. Comma Splices


Wrong: "I love writing, it helps me think."
Right: "I love writing; it helps me think." or "I love writing because it helps me think."



3. Its vs. It's


"It's" is a contraction of "it is." "Its" is possessive. If you can replace it with "it is," use "it's."



4. Their/There/They're


"Their" = possessive, "there" = location, "they're" = they are. Always double-check which one you mean.



5. Dangling Modifiers


Wrong: "Walking to class, the rain started."
Right: "Walking to class, I got caught in the rain."



6. Misplaced Apostrophes


Apostrophes show possession or contractions, not plurals. "The dog's bone" (one dog), "The dogs' bones" (multiple dogs), "The dogs ran" (no apostrophe for plurals).



7. Who vs. Whom


"Who" is a subject pronoun (like he/she). "Whom" is an object pronoun (like him/her). If you can answer the question with "him," use "whom."



8. Affect vs. Effect


"Affect" is usually a verb (to influence). "Effect" is usually a noun (a result). "The rain affects my mood. The effect of rain is calming."



9. Run-On Sentences


Two independent clauses need proper connection: a period, semicolon, or conjunction. Don't just smash them together.



10. Inconsistent Tense


Pick a tense and stick with it. Shifting between past and present confuses readers.



Use our grammar checker to catch these mistakes automatically in your writing.