Even advanced English speakers make grammar mistakes. Some errors are so common that they appear in everyday conversation, emails, and professional writing. This comprehensive guide covers the 30 most frequent English grammar mistakes, explains why they are wrong, and shows you exactly how to fix them. Bookmark this page as your go-to grammar checklist.
How to Use This Guide
Each mistake is organized with a clear pattern: the wrong version, the correct version, and a brief explanation of the rule. Study the ones you recognize in your own writing and practice the corrections.
Common Mistakes with Verbs
1. Subject-Verb Agreement
Wrong: The list of items are on the table. Right: The list of items is on the table. Rule: The verb agrees with the subject (list), not the nearest noun (items).
2. Using the Wrong Tense After "If"
Wrong: If I will see him, I will tell him. Right: If I see him, I will tell him. Rule: In first conditional, use present simple after "if," not "will."
3. Confusing Past Simple and Present Perfect
Wrong: I have gone to Paris last year. Right: I went to Paris last year. Rule: Use past simple with specific past time expressions (yesterday, last year, in 2020).
4. Forgetting the Third-Person -s
Wrong: She go to school every day. Right: She goes to school every day. Rule: Add -s or -es to verbs in the present simple for he/she/it.
5. Using "Did" with a Past Form
Wrong: Did you went to the store? Right: Did you go to the store? Rule: After "did," always use the base form of the verb.
Common Mistakes with Articles
6. Missing Articles
Wrong: She is teacher. Right: She is a teacher. Rule: Singular countable nouns need an article (a, an, the) or determiner.
7. Using "A" Instead of "An"
Wrong: She ate a apple. Right: She ate an apple. Rule: Use "an" before words that start with a vowel sound (not just a vowel letter).
8. Unnecessary "The"
Wrong: I like the music. (in general) Right: I like music. Rule: Do not use "the" when talking about things in general.
Common Mistakes with Pronouns
9. Me vs. I
Wrong: John and me went to the party. Right: John and I went to the party. Rule: Use I as a subject. Test by removing the other person: "I went to the party."
10. Who vs. Whom
Wrong: Who did you give the book to? Right: Whom did you give the book to? (formal) Rule: Use "whom" when it is the object. If you can replace it with "him/her," use "whom."
11. Its vs. It's
Wrong: The dog wagged it's tail. Right: The dog wagged its tail. Rule: "Its" = possessive. "It's" = it is / it has.
Common Mistakes with Prepositions
12. Depend On (Not Depend Of)
Wrong: It depends of the weather. Right: It depends on the weather. Rule: The correct collocation is "depend on."
13. Interested In (Not Interested At/For)
Wrong: I am interested for learning English. Right: I am interested in learning English. Rule: The correct preposition is "interested in."
14. Listen To (Not Listen -)
Wrong: I like to listen music. Right: I like to listen to music. Rule: "Listen" requires the preposition "to" before the object.
15. Different From (Not Different Than/To)
Wrong: This is different than that. Right: This is different from that. (standard) Rule: In standard English, use "different from."
Common Mistakes with Word Confusion
16. Their / There / They're
Wrong: Their going to the park. There dog is big. Right: They're going to the park. Their dog is big. Rule: They're = they are. Their = possessive. There = place.
17. Your / You're
Wrong: Your welcome. Right: You're welcome. Rule: You're = you are. Your = possessive.
18. Then vs. Than
Wrong: She is taller then her brother. Right: She is taller than her brother. Rule: "Than" is for comparisons. "Then" is for time sequence.
19. Lose vs. Loose
Wrong: Don't loose your keys. Right: Don't lose your keys. Rule: "Lose" (verb) = to misplace. "Loose" (adjective) = not tight.
20. Affect vs. Effect
Wrong: The weather effected my mood. Right: The weather affected my mood. Rule: "Affect" is usually a verb. "Effect" is usually a noun.
Common Mistakes with Sentence Structure
21. Run-On Sentences
Wrong: I love cooking I make dinner every night. Right: I love cooking. I make dinner every night. / I love cooking, and I make dinner every night. Rule: Do not join two independent clauses without a conjunction or punctuation.
22. Comma Splices
Wrong: She was tired, she went to bed. Right: She was tired, so she went to bed. Rule: Two independent clauses need a conjunction, semicolon, or period — not just a comma.
23. Double Negatives
Wrong: I don't have nothing. Right: I don't have anything. / I have nothing. Rule: Standard English uses only one negative per clause.
24. Although... But
Wrong: Although it was raining, but we went outside. Right: Although it was raining, we went outside. Rule: "Although" and "but" both show contrast — use only one.
25. Misplaced Modifiers
Wrong: She almost drove her kids to school every day. (Does she almost drive, or does she drive almost every day?) Right: She drove her kids to school almost every day. Rule: Place modifiers next to the words they describe.
Common Mistakes with Adjectives and Adverbs
26. Good vs. Well
Wrong: She sings very good. Right: She sings very well. Rule: "Good" is an adjective. "Well" is an adverb that modifies verbs.
27. Less vs. Fewer
Wrong: There are less students this year. Right: There are fewer students this year. Rule: "Fewer" = countable nouns. "Less" = uncountable nouns.
28. Comparative and Superlative Errors
Wrong: She is more smarter than her sister. Right: She is smarter than her sister. Rule: Do not use "more" with adjectives that already have -er endings.
29. Adjective Order
Wrong: She bought a red beautiful big dress. Right: She bought a beautiful big red dress. Rule: English adjective order: opinion, size, age, shape, color, origin, material, purpose.
30. Bored vs. Boring
Wrong: I am boring with this movie. Right: I am bored with this movie. / This movie is boring. Rule: -ed adjectives describe feelings. -ing adjectives describe the thing causing the feeling.
When to Use This Reference
Review this list before you:
- Submit an essay or assignment
- Send a professional email
- Take an English proficiency exam (IELTS, TOEFL, Cambridge)
- Proofread any important document
Practice Examples
Identify and correct the mistakes in these sentences:
- Wrong: Me and him went to the store yesterday. Right: He and I went to the store yesterday.
- Wrong: I have less friends than before. Right: I have fewer friends than before.
- Wrong: If I will pass the exam, I will celebrate. Right: If I pass the exam, I will celebrate.
- Wrong: The informations are incorrect. Right: The information is incorrect. ("Information" is uncountable.)
- Wrong: She is more taller than me. Right: She is taller than I am.
- Wrong: I am agree with you. Right: I agree with you. ("Agree" is a verb, not an adjective.)
Quick Reference
- Verbs: Check subject-verb agreement, use the correct tense after "if," do not add -s after auxiliary verbs.
- Articles: Singular countable nouns need a/an/the. No "the" for general statements.
- Pronouns: I = subject, me = object. Its = possessive, it's = it is.
- Prepositions: depend on, interested in, listen to, different from.
- Word pairs: their/there/they're, your/you're, then/than, lose/loose, affect/effect.
- Sentence structure: Avoid run-ons, comma splices, double negatives, and although+but.
- Adjectives/Adverbs: good (adjective) vs. well (adverb), fewer (countable) vs. less (uncountable), -ed (feelings) vs. -ing (cause).
Keep this list as a reference and check it every time you write. Over time, these corrections will become automatic, and your English grammar will improve dramatically.
