Did you know? The apostrophe in “who’s” marks a contraction, while the possessive “whose” has no apostrophe.
Use who’s when the meaning is who is or who has. Use whose to ask about possession or connection, or to introduce a relative clause showing that relationship. So write Who’s ready? but Whose bag is this?
The apostrophe in who’s marks missing letters in a contraction; it does not make the word possessive. Whose has no apostrophe even though it is the possessive form, just as his, hers and its have no possessive apostrophe.
Try this now: replace the word with who is or who has. If the expanded sentence works, choose who’s. If it does not and the sentence asks “belonging to whom?” or links something to a person or thing, choose whose.
Choose the task you need
Expand who’s before deciding
Who’s is a contraction. The expansion test is therefore the fastest first check: substitute who is or who has and listen for the intended grammar and meaning.
| Sentence | Expansion | Choice |
|---|---|---|
| Who’s at the door? | Who is at the door? | who’s |
| Who’s finished the task? | Who has finished the task? | who’s |
| Whose coat is wet? | Who is coat is wet? ✗ | whose |
| The pupil whose coat is wet waited inside | The pupil who is coat is wet ✗ | whose |
The expansion must fit the whole sentence, not just sound vaguely familiar. Who has works in a present-perfect form such as who has finished, but not as a substitute for every occurrence of whose.
Use whose for possession and wider relationships
Cambridge Grammar describes whose as a wh-word used in questions about possession and in relative clauses. “Possession” is a useful starting label, but the relationship can be broader than literal ownership.
| Use | Example | Relationship |
|---|---|---|
| Direct question | Whose pencil is this? | The pencil belongs to someone |
| Pronoun on its own | Whose is the blue one? | The noun is understood |
| Relative clause about a person | The student whose answer was clear explained it. | Answer associated with the student |
| Relative clause about a thing | A book whose ending surprised us won the prize. | Ending belongs to or is part of the book |
This matters in secondary writing: whose can refer to people, animals and things when it introduces a possessive or associative relative clause.
Do not let the apostrophe signal possession here
Many learners overgeneralise the useful rule that apostrophes can show possession in nouns. Pronouns follow their own patterns. In who’s, the apostrophe signals omitted letters; the possessive word is whose.
Original teaching routine: name the apostrophe’s job
- Can the form expand to two words? If yes, the apostrophe marks a contraction.
- Is the sentence asking about belonging or association? If yes, test whose.
- Do not add an apostrophe merely because something belongs to someone.
- Compare it’s/its and who’s/whose as parallel contraction–possessive pairs.
Naming the apostrophe’s job is stronger than memorising that one form “looks possessive”. It transfers to editing other contractions and possessive pronouns.
Diagnose why the wrong form was chosen
| Observed choice | Likely reasoning | Useful prompt |
|---|---|---|
| Who’s bag is this? | Apostrophe assumed to mark possession | Can you expand it to “who is”? |
| Whose coming with us? | Chooses by sound | Would “who is coming” work? |
| The team who’s captain spoke… | Sees a person and chooses who’s | Does the sentence mean “who is captain” or “the team’s captain”? |
| Whose completed the work? | Confuses whose with who has | Which two words have been shortened? |
Because the words sound the same in most speech, repeated oral practice alone may not repair the spelling. The learner needs a visible expansion-and-relationship check during writing and editing.
Apply the choice in compositions and editing
During a first draft, fluency can come before correction. During editing, circle every who’s and whose, run the expansion test and then read the full sentence for reference. In a relative clause, make sure the reader can tell which person, animal or thing whose refers to.
- Use who’s only for who is or who has.
- Use whose for “belonging or connected to whom/which”.
- Check the noun or idea immediately linked to whose.
- Keep the correction in context so the sentence still says what the writer intends.
A compact explanation is: “Who’s is a contraction, so I can expand it. Whose shows possession or connection, so I cannot replace it with who is or who has.”
Current pathway note, checked 12 October 2026: Posting Groups 1, 2 and 3 support admission to secondary schools; they are not subject levels. Individual secondary subjects may be taken at G1, G2 or G3 according to the student’s programme and the subject available. See MOE’s Full Subject-Based Banding overview. The Singapore-Cambridge Secondary Education Certificate (SEC) begins in 2027. The applicable syllabus depends on the subject, level, examination year and candidate type; not every subject is available at every level.
A calm next step
If the two forms are chosen by sound, bring a short unedited paragraph. The useful next step is to see whether the learner can expand the contraction and identify the possession or relationship before changing the spelling.
eduKateSG’s verified 3-pax positioning allows close attention to the exact step where an answer begins to drift. There is no grade guarantee; the useful question is whether the teaching response matches the learner’s observed error.
Ask eduKateSG about a 3-pax learning conversation. Bring one recent piece of work so the discussion can begin with evidence.
Sources and checking notes
- Cambridge Grammar, Whose
- Merriam-Webster, Who’s vs Whose
- MOE, Full Subject-Based Banding
- SEAB, Singapore-Cambridge Secondary Education Certificate
Teaching examples and diagnostic routines in this guide are original eduKateSG illustrations. Policy links and supporting sources were checked on 12 October 2026.