When somebody else finds a grammar mistake in your work, it can be embarrassing. But don’t let it get to you—we all make grammar mistakes.

Common grammar mistakes include punctuation and syntax errors and incorrect word choices. Grammar mistakes often make it difficult for readers to understand a piece of writing; this is why writers should try to avoid them.

The goal is to have polished, clear, mistake-free writing, so we’ll look at some of the most common mistakes so you know how to identify, fix, and avoid them.

30 common grammar mistakes

1 Your vs. you’re 2 Who vs. whom 3 Who’s vs. whose 4 Affect vs. effect 5 Who vs. that 6 That vs. which 7 I.e. vs. e.g. 8 Then vs. than 9 Each and every 10 More than vs. over 11 Less vs. fewer 12 Me vs. I 13 A lot vs. allot vs. a lot 14 Farther vs. further 15 Like vs. such as 16 May vs. might 17 Past vs. passed 18 Based off vs. based on  19 Compliment vs. complement 20 Misplaced modifiers 21 Passive voice 22 Possessive nouns 23 Commas 24 Semicolons 25 Title capitalization 26 Apostrophes 27 Punctuation’s place in parentheses 28 Incomplete comparisons 29 Em dash vs. en dash vs. hyphen 30 Subject/verb agreement