Master the possessive versus contraction puzzle with an unbreakable rule. Never second-guess this apostrophe decision again.

The Absolute Rule

• Whose = Possessive (ownership)
• Who's = Contraction (who is/who has)

No exceptions. Ever.

Whose: The Possessive Form

Whose shows ownership or belonging, never uses an apostrophe.

Direct Possession

• Whose book is this?
• Whose idea was that?
• Whose car is parked outside?
• Whose turn is it?

In Clauses

• The student whose essay won
• A company whose values align
• The dog whose owner called
• Anyone whose name starts with A

Abstract Possession

• A theory whose time has come
• The building whose foundation cracked
• A decision whose impact lasted

Memory Device

WHOSE = WHO poSsessEs (no apostrophe, like his/hers/its)

Who's: The Contraction

Who's ONLY means "who is" or "who has"—always test by expanding.

"Who Is" Examples

• Who's calling? (Who is calling?)
• Who's responsible? (Who is responsible?)
• Who's your favorite? (Who is your favorite?)
• I know who's coming (who is coming)

"Who Has" Examples

• Who's been here? (Who has been here?)
• Who's finished? (Who has finished?)
• Who's got the keys? (Who has got the keys?)
• Someone who's traveled (who has traveled)

Memory Device

WHO'S = WHO IapostrophS (apostrophe shows missing letters)

The Foolproof Test

Expand "who's" to "who is" or "who has":

• Makes sense? → Use who's
• Doesn't work? → Use whose

Test Examples

1. "(Whose/Who's) ready?"

   • Test: "Who is ready?" ✓
   • Answer: Who's

2. "(Whose/Who's) phone is ringing?"

   • Test: "Who is phone is ringing?" ✗
   • Answer: Whose

3. "The artist (whose/who's) painting this"

   • Test: "The artist who is painting this" ✓
   • Answer: who's (if currently painting)
   • Test: "The artist whose painting this [is]" ✓
   • Answer: whose (if owns the painting)

Common Mistakes to Avoid

Autocorrect Issues

Phones often incorrectly change "whose" to "who's"—always double-check!

Formal Writing

• ❌ "The company who's profits increased"
• ✅ "The company whose profits increased"

Questions

• ❌ "Whose coming to dinner?"
• ✅ "Who's coming to dinner?"

Quick Reference

Context	Use Whose	Use Who's
Shows ownership	✓
Can expand to "who is"		✓
Can expand to "who has"		✓
Possessive question	✓
Before a noun	Usually ✓	Rarely

Practice Exercise

Select the correct form:

1. (Whose/Who's) jacket is this?
2. I wonder (whose/who's) going to win.
3. The teacher (whose/who's) class I'm in is excellent.
4. (Whose/Who's) been eating my lunch?
5. (Whose/Who's) responsibility is it?
6. Anyone (whose/who's) interested should sign up.
7. The car (whose/who's) alarm is going off should be moved.
8. Tell me (whose/who's) coming tonight.
9. (Whose/Who's) side are you on?
10. A friend (whose/who's) always there for you is rare.

Answer Key: 1. Whose, 2. who's, 3. whose, 4. Who's, 5. Whose, 6. who's, 7. whose, 8. who's, 9. Whose, 10. who's

Final tip: Whose owns things (no apostrophe). Who's is always "who is" or "who has" (apostrophe shows contraction). It's that simple!