How to Use Apostrophes (and Avoid Common Mistakes)

Apostrophes are one of the most commonly misused punctuation marks. They might seem small, but using them incorrectly can make your writing look unprofessional. This guide will break down the two main jobs of an apostrophe and help you avoid the most common mistakes.

The Two Main Jobs of an Apostrophe

1. To Show Possession

Apostrophes are used to show that something belongs to someone or something.

For singular nouns, add an apostrophe + "s":

• "The dog's bone."
• "Sarah's car."
• "The company's logo."

For plural nouns that end in "s," just add an apostrophe:

• "The dogs' bones."
• "The students' projects."
• "The companies' logos."

For plural nouns that don't end in "s," add an apostrophe + "s":

• "The children's toys."
• "The people's choice."

2. To Form Contractions

Apostrophes are used to show that letters have been left out.

• it's = it is
• who's = who is
• don't = do not
• can't = cannot
• you're = you are

Common Mistakes to Avoid

1. Plurals

Never use an apostrophe to make a noun plural.

• ❌ Incorrect: "I love dog's."
• ✅ Correct: "I love dogs."

This is one of the most common and most jarring apostrophe mistakes.

2. "Its" vs. "It's"

This is a big one.

• It's is a contraction of "it is."

• Its is a possessive pronoun.

• Correct: "It's a beautiful day."

• Correct: "The dog wagged its tail."

3. "Your" vs. "You're"

• You're is a contraction of "you are."

• Your is a possessive pronoun.

• Correct: "You're going to do great."

• Correct: "Is this your book?"

4. "Whose" vs. "Who's"

• Who's is a contraction of "who is."

• Whose is a possessive pronoun.

• Correct: "Who's coming to the party?"

• Correct: "Whose jacket is this?"

5. "There," "Their," and "They're"

• They're is a contraction of "they are."

• Their is a possessive pronoun.

• There refers to a place.

• Correct: "They're going to be late."

• Correct: "That is their house."

• Correct: "The book is over there."

A Quick Test

1. Are you trying to show that something belongs to something else? → Use a possessive apostrophe.
2. Are you shortening a word by leaving out letters? → Use a contraction apostrophe.
3. Are you just making a word plural? → Don't use an apostrophe.

Test Yourself

Choose the right word:

1. (Its/It's) a beautiful day.
2. The dog wagged (its/it's) tail.
3. (Your/You're) doing a great job.
4. Is this (your/you're) coat?
5. (Whose/Who's) coming to dinner?
6. (Whose/Who's) keys are these?
7. (They're/Their/There) going to the park.
8. That is (they're/their/there) car.
9. The book is over (they're/their/there).
10. The (students/student's/students') projects are due on Friday. (plural)

Answer Key:

1. It's
2. its
3. You're
4. your
5. Who's
6. Whose
7. They're
8. their
9. there
10. students'

Final Thoughts

Apostrophes might seem tricky, but they follow a few simple rules. By mastering these rules, you can make your writing clearer, more professional, and more effective.