Whose vs Who's: Test Possession Against Expansion

Reviewed by the Grammarlyzer Editorial Team · Our Review Standards · Published January 22, 2026 · Updated July 16, 2026

A possessive wh-word versus the short form of who is or who has

Quick Answer

Use whose when you ask who something belongs to or connect a person, animal, or thing to something associated with it: Whose notes are these? or the analyst whose notes we used.

Use who's when the words expand to who is or who has: Who's ready? or Who's submitted the form?

Expand before you inspect possession

Try both expansions. If either one fits the intended sentence, write who's. If neither fits, locate the thing possessed or associated and test whose.

Four Slots That Settle the Choice

Form and slotWhat it doesExampleDiagnostic
whose + nounAsks about possession before the named itemWhose access card is this?Which person is linked to the card?
whose aloneAsks about possession without repeating the itemWhose is the blue one?The item is supplied by the surrounding context.
noun + whose + clauseIntroduces a relative clause indicating possession or associationthe editor whose notes arrivedThe notes are associated with the editor.
who's + complementShortens who is or who hasWho's already replied?Who has already replied? preserves the sentence.

The broader possessives and contractions guide compares several apostrophe families. This page stays with the specific question and relative-clause slots where whose competes with the two possible expansions of who's.

Whose Has Three Useful Patterns

Cambridge describes whose as a wh-word used for possession in questions and relative clauses. The noun after it is common, but not required in every question.

Direct question before a noun:

Whose signature is missing?

Whose asks which person is linked to the signature.
Standalone question:

Whose is the unsigned copy?

The context supplies the item, so whose stands alone.
Indirect question:

Can you confirm whose the unsigned copy is?

The possession question is embedded after confirm.
Relative clause:

The editor whose signature is missing has been notified.

Whose links the signature to the editor.

A thing can be the antecedent

Supported pattern:

The report whose appendix is missing needs revision.

Cambridge records relative whose for possession by people, animals, and things. This focused page treats that apostrophe decision; the relative clauses guide handles the wider connector and clause-type choices.

Who's Has Two Expansions

Cambridge lists who's as the short form of both who is and who has. Test both because checking only who is can misdiagnose a perfect construction.

ContractionExpansionWhy it fits
Who's responsible?Who is responsible?Is links who to the adjective responsible.
Who's reviewing the draft?Who is reviewing the draft?Is helps form the present continuous.
Who's submitted the draft?Who has submitted the draft?Has helps form the present perfect.
Who's been assigned?Who has been assigned?The expansion contains the passive perfect phrase has been assigned.

Sometimes both expansions are grammatical

Who's finished? can mean Who is finished? or Who has finished? The surrounding meaning decides the expansion, but the spelling remains who's either way.

The Expansion-and-Possession Audit

  1. Try who is. If it supplies the subject and verb while preserving the intended meaning, choose who's.
  2. Try who has. Look especially for a following past participle such as sent, finished, chosen, or been.
  3. If both expansions fail, locate the possession relation. Ask which person, animal, or thing is linked to the following noun or relative clause.
  4. Check whether the item is stated or understood. Write whose before a noun or alone when context supplies the item.
  5. Reread the complete clause. One sentence can need both forms: Who's the editor whose notes arrived?

Five Repairs and Their Clause Tests

Before:

Whose responsible for the final approval?

After:

Who's responsible for the final approval?

Who is responsible supplies the subject, linking verb, and adjective.
Before:

Who's approval is still missing?

After:

Whose approval is still missing?

Neither who is approval nor who has approval fits this structure. The question asks which person is linked to the approval.
Before:

The reviewer who's comments we accepted has replied.

After:

The reviewer whose comments we accepted has replied.

Whose introduces the relative clause and links the comments to the reviewer.
Before:

Do you know whose already submitted the revision?

After:

Do you know who's already submitted the revision?

The embedded clause expands to who has already submitted.
Before:

Whose the editor who's notes arrived?

After:

Who's the editor whose notes arrived?

The first form expands to Who is; the second creates the possessive relative link between the editor and the notes.

Live Check: The Target Swap Is a Recorded Miss

The local browser test did not flag the apostrophe error in the starter sentence below. Run the exact case to see why the manual audit still matters.

Manual correction: The analyst whose report was late apologized.

Honest limits: The engine returned no issues for both the incorrect starter and the corrected sentence. Because both spellings are dictionary forms, expand who's and inspect the possession slot even when the tool is silent.

Frequently Asked Questions

What is the difference between whose and who's?

Whose is a wh-word used to ask about or express possession. Who's is the short form of who is or who has. Expand the apostrophe form first, then check whether the sentence instead needs a possessive relation.

What is the quickest test for whose or who's?

Replace the word with who is and then who has. If one expansion preserves the grammar and intended meaning, use who's. If neither works and the sentence asks who something belongs to or links something to a possessor, use whose.

Can whose stand alone without a noun after it?

Yes. Cambridge gives Whose are these gloves? as a question about possession. In a sentence such as Whose is the unsigned copy?, whose stands alone rather than appearing directly before a noun.

Can whose refer to a thing in a relative clause?

Yes. Cambridge records whose in relative clauses indicating possession by people, animals, and things. The report whose appendix is missing is therefore grammatical even though report is not a person.

Does Grammarlyzer catch every whose and who's swap?

No. In the recorded browser test it did not flag The analyst who's report was late apologized. The corrected sentence with whose also returned no issues, so use the expansion-and-possession audit even after an automated check.

Sources and Editorial Boundaries

The two Cambridge entries below directly support the retained grammar claims. The four-slot comparison, five-step audit, and repair explanations are Grammarlyzer editorial analysis applying those documented forms to sentence structure.

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