Commonly confused words
1. Your vs. you're
Your shows possession; you're means “you are”. ✗ Your welcome. ✓ You're welcome. Test: if “you are” fits, use you're.
2. Its vs. it's
It's means “it is” or “it has”. Its is possessive and has no apostrophe, like his and hers. ✗ The company changed it's logo. ✓ The company changed its logo.
3. Their, there and they're
Their = belonging to them. There = a place, or “there is/are”. They're = “they are”. ✓ They're bringing their laptops over there.
4. Then vs. than
Than compares; then is about time. ✗ She's taller then me. ✓ She's taller than me.
5. Affect vs. effect
Usually, affect is the verb and effect is the noun. ✓ The new policy will affect everyone. The effect was immediate. Remember: Affect is an Action, Effect is an End result.
6. Lose vs. loose
Lose (one o) means to misplace or fail to win. Loose (two o's) means not tight. ✓ Don't lose the loose screw.
7. Compliment vs. complement
A compliment is praise. A complement completes something. ✓ The wine complements the meal. Remember: complement completes.
8. Principal vs. principle
A principle is a rule or belief. Principal means main, or the head of a school. ✓ The principal reason is a matter of principle.
9. Everyday vs. every day
Everyday is an adjective meaning ordinary; every day means each day. ✓ I wear my everyday shoes every day.
10. A lot, not alot
Alot isn't a word. ✓ Thanks a lot. (Allot, meaning to share out, is a different word.)
Verb and grammar mistakes
11. Could of, should of, would of
These come from how could've sounds when spoken. ✗ I could of helped. ✓ I could have helped.
12. Subject-verb agreement with “each” and “everyone”
Each, everyone, everybody and nobody are singular. ✗ Everyone need a break. ✓ Everyone needs a break.
13. Lie vs. lay
You lie down yourself; you lay something down. ✓ I'm going to lie down. Lay the book on the table. (The past tense of lie is lay, which is why it's confusing: Yesterday I lay in bed.)
14. Fewer vs. less
Use fewer for things you can count and less for amounts. ✓ Fewer calories, less sugar. ✓ Fewer than ten people.
15. Who vs. whom
Who does the action; whom receives it. Test: if you'd answer with he, use who; if him, use whom. ✓ Who called? (He called.) To whom did you send it? (I sent it to him.)
16. Me vs. I
Remove the other person to check. ✗ Between you and I. ✓ Between you and me. ✓ Sam and I went (because you'd say “I went”, not “me went”).
Punctuation and structure
17. Comma splices
Two complete sentences can't be joined with just a comma. ✗ It's late, I'm going home. ✓ It's late, so I'm going home. ✓ It's late. I'm going home. ✓ It's late; I'm going home.
18. Apostrophes in plurals
Plurals don't take apostrophes. ✗ Apple's for sale. ✓ Apples for sale. ✓ The 1990s, not the 1990's.
19. i.e. vs. e.g.
e.g. means “for example”; i.e. means “that is”, and introduces the only thing you mean. ✓ Bring a fruit, e.g. an apple or a banana. ✓ Bring the main ingredient, i.e. flour.
20. Dangling modifiers
The opening phrase must describe the subject that follows it. ✗ Walking to work, the rain started. (The rain wasn't walking.) ✓ Walking to work, I got caught in the rain.
How to catch these mistakes
- Read your writing aloud. Your ear catches errors your eye skips over.
- Leave a gap. Proofread after a break, or the next day, so you read what's on the page rather than what you meant.
- Search for your weak spots. If you often mix up its and it's, search your document for both and check each one.
- Use a checker as a second pair of eyes. Paste your text into the grammar checker, which flags every mistake on this list and suggests a fix.
Grammar is only part of clear writing. To make sure your text is easy to read, run it through the readability checker as well.