Interrogative pronouns are pronouns used to ask questions about people, things, or information that needs to be identified. The five main interrogative pronouns in English are who, whom, whose, which, and what.
Suppose a research team receives an unsigned report alongside three proposed designs. Before moving forward, the team needs to know:
Who prepared the report?
Which of the three designs was approved?
What caused the figures to change?
Each question asks for different information. Who asks for a person’s identity, which asks for a choice from an identified group, and what asks about the cause of an event.
Interrogative pronouns can appear in direct questions or in questions embedded within other sentences. Their use depends on the information being requested and their grammatical function.
Interrogative Pronouns List
English has five main interrogative pronouns.
| Interrogative pronoun | Main use | Example |
|---|---|---|
| Who | Asking about a person or people | Who recommended the revised treatment plan? |
| Whom | Asking about a person as an object, mainly in formal English | To whom should the completed documents be sent? |
| Whose | Asking about possession or association | Whose are the photographs on this table? |
| Which | Identifying an option from an understood set | Which of the available dates works best? |
| What | Asking about things, events, or other information | What interrupted the live broadcast? |
These words represent the information being requested.
For example:
Who arranged the exhibition?
A possible answer is the museum’s events coordinator.
Which was selected for publication?
The answer might be the second manuscript, provided the manuscripts are already understood from the conversation.
An interrogative pronoun does not always need a previously mentioned noun. Often, the speaker uses it precisely because the answer is unknown.
Who vs. Whom
Who and whom both refer to people.
In traditional grammar, who is the subject form, while whom is the object form.
Compare:
Who contacted the supplier?
The question asks which person performed the action.
Whom did the supplier contact?
Here, whom is the object of contact. The supplier performed the action, and the question asks which person received it.
In modern English, however, who is widely used as an object.
Who did the supplier contact?
This is natural in everyday conversation and standard contemporary usage.
The form whom remains appropriate, particularly in formal writing, but it is not necessary in most ordinary object questions.
When Whom Is More Natural
Whom is particularly common after a preposition placed at the beginning of a formal question.
Compare:
Who should we send the signed agreement to?
To whom should we send the signed agreement?
The first sounds natural in everyday English. The second is more formal and may suit legal or official correspondence.
Both are grammatical. Ending a question with a preposition is normal English usage.
Who or Whom in Longer Sentences
A longer question can make the distinction harder to recognize.
Who do you think will manage the new department?
Who is the subject of will manage.
Now compare:
Who do you think the directors appointed to manage the department?
Here, who is the object of appointed.
In formal writing, the second question could use whom:
Whom do you think the directors appointed to manage the department?
The pronoun’s function depends on its role within the relevant clause, not simply on the words immediately surrounding it.
One useful check is to imagine the answer.
She will manage the department.
She is the subject, so who is appropriate.
The directors appointed her.
Her is the object, so formal whom is possible.
This test can help with complicated sentences, although everyday English generally favors who in object questions.
What vs. Which
What and which can both ask about things, but they often present the possible answers differently.
What usually asks for information from a relatively open range of possibilities.
What would you recommend for the next training session?
The speaker is inviting suggestions without identifying a particular set of choices.
Which commonly asks someone to choose from options already known or understood.
We have three training formats available. Which would you recommend?
The speaker and listener know the available options.
When Both What and Which Are Possible
Suppose a publisher is choosing artwork for a book cover.
Before the design team prepares any options, the publisher might ask:
What would work best for the cover?
The answer could be a photograph, an illustration, a typographic design, or something else.
After reviewing several designs, the publisher might ask:
Which would work best for the cover?
Now the question directs attention to the available designs.
Both are grammatical. The difference is how the speaker presents the possible answers.
Is Which Only Used for a Small Number of Options?
No. Which is not limited to two or three choices.
It can refer to a large group when the relevant options are identifiable.
Which of the shortlisted applicants has experience in public health research?
The question concerns an understood group of applicants.
Which can also ask about people when the speaker is selecting from a known set.
The distinction between what and which is therefore not a fixed rule about how many choices exist. The context and the speaker’s perspective matter more.
Which Is or Which Are?
The number of people or things being asked about can affect verb agreement.
Compare:
Which of these reports is missing?
Which of these reports are missing?
The first treats the missing report as singular. The second asks about missing reports as a plural group.
Similarly:
Which of the shortlisted candidates has accepted the offer?
Which of the shortlisted candidates have accepted the offer?
Both are grammatical.
The singular form asks for an individual candidate, while the plural form allows for a plural answer. The question’s wording reflects how the speaker frames the answer, not necessarily what the actual answer will turn out to be.
Whose: Asking About Possession
Whose asks who owns something or who is associated with it.
Imagine several photographs have been left on a table after a workshop. The organizer asks:
Whose are these?
The speaker wants to know who the photographs belong to.
Here, whose is an interrogative pronoun because it stands independently.
Another example:
These two laptops were left in the meeting room. Whose is the silver one?
The question asks for the owner of the silver laptop.
In everyday conversation, a speaker might instead ask Who does the silver one belong to? or Whose laptop is the silver one?
Those alternatives are natural, but in the second, whose is a determiner rather than an independent pronoun.
Whose vs. Who’s
Whose and who’s sound alike but have different meanings.
Whose asks about possession:
Whose are these reference books?
Who’s is a contraction of who is or who has.
Who’s responsible for preparing the final report?
Here, who’s means who is.
Who’s already reviewed the final report?
Here, it means who has.
If who’s can be expanded to who is or who has without changing the intended meaning, the contraction is appropriate.
Interrogative Pronouns vs. Other Question Words
A word can introduce a question without functioning as an interrogative pronoun. Its grammatical role determines the distinction.
Interrogative Pronouns vs. Interrogative Determiners
What, which, and whose can stand independently as pronouns or appear before nouns as determiners.
Compare:
Which received the highest rating?
Which proposal received the highest rating?
In the first sentence, which is an interrogative pronoun. The available options are already understood.
In the second, which is a determiner used with proposal.
The same distinction applies to what and whose.
| Interrogative pronoun | Interrogative determiner |
|---|---|
| What caused the damage? | What equipment caused the damage? |
| Which arrived first? | Which shipment arrived first? |
| Whose are these folders? | Whose folders are these? |
An important distinction appears with which of:
Which of the shortlisted proposals was approved?
Which still functions independently as an interrogative pronoun. The phrase of the shortlisted proposals identifies the group from which the answer is selected.
The presence of a noun later in the expression does not automatically make which a determiner.
Traditional grammar often calls the determiner forms interrogative adjectives.
Interrogative Pronouns vs. Interrogative Adverbs
Words such as where, when, why, and how also introduce questions, but they are not normally classified as interrogative pronouns.
| Question | Information requested |
|---|---|
| Who supervised the installation? | A person’s identity |
| What caused the interruption? | An event or cause |
| Where was the equipment installed? | A location |
| When did the installation finish? | A time |
| Why was the installation delayed? | A reason |
| How was the equipment transported? | A method |
In traditional grammar, where, when, why, and how are commonly described as interrogative adverbs.
They ask about circumstances rather than functioning as pronouns referring to people or things.
Interrogative Pronouns vs. Relative Pronouns
Some interrogative forms can also introduce relative clauses.
Compare:
Who verified the figures?
The analyst who verified the figures will present the report.
In the first sentence, who asks for a person’s identity.
In the second, who introduces a relative clause describing the analyst.
The word’s function changes even though its spelling remains the same.
An interrogative clause can also appear inside a statement:
We need to establish who verified the figures.
Here, who verified the figures is an embedded question. It expresses the information that needs to be established rather than describing a preceding noun.
What About Whoever, Whatever, and Whichever?
Compound forms such as whoever, whatever, and whichever have different grammatical uses.
Some appear in emphatic questions:
Whatever happened to the original contract?
The speaker is asking about the contract, possibly with surprise or concern.
In another sentence:
Choose whichever suits the project requirements.
Whichever expresses a free choice. It is not asking a question.
These forms should not automatically be classified as interrogative simply because they resemble question words.
How Interrogative Pronouns Affect Question Structure
The grammatical role of an interrogative pronoun affects how a question is formed.
One important distinction is whether the question asks about the person performing an action or the person receiving it.
Subject Questions vs. Object Questions
Suppose a journalist interviewed a museum curator.
We can ask two questions about the same event.
| Question | Possible answer | Role of who |
|---|---|---|
| Who interviewed the curator? | The journalist interviewed the curator. | Subject |
| Who did the journalist interview? | The journalist interviewed the curator. | Object |
The first question asks for the person who performed the action.
The second asks for the person the journalist interviewed.
In ordinary subject questions using the simple present or past tense, we do not normally add do, does, or did merely to form the question.
Who discovered the discrepancy?
In an ordinary object question with a simple past-tense lexical verb, did appears before the subject.
Who did the auditor contact?
The auditor is the subject, while who is the object of contact.
The distinction also applies to what and which.
What caused the alarm?
What is the subject.
What did the technician inspect?
What is the object.
Questions involving be, other auxiliary verbs, or modal verbs follow the relevant question patterns.
An auxiliary can also appear for emphasis in a subject question:
Who did authorize the payment?
The emphatic did does not make who an object.
Direct and Embedded Questions
Interrogative pronouns also appear in questions embedded within larger sentences.
Compare:
What did the reviewers recommend?
We haven’t established what the reviewers recommended.
The first is a direct question.
In the second sentence, the question appears within a statement. The embedded clause uses the order the reviewers recommended, rather than the direct-question order did the reviewers recommend.
Another comparison:
Which design did the committee approve?
The director asked which design the committee approved.
The embedded clause does not retain direct-question inversion.
When the interrogative pronoun itself is the subject, the word order may look unchanged.
Who approved the revised budget?
The committee wants to know who approved the revised budget.
In both clauses, who is the subject of approved.
A complete sentence can also be a direct question while containing an embedded question:
Can you tell me what the reviewers recommended?
The whole sentence takes a question mark because Can you tell me …? is a direct question. Inside it, what the reviewers recommended keeps embedded-question word order.
Choosing the Right Question in Context
A question can be grammatically correct without asking for the exact information someone needs.
Imagine a university committee reviewing two shortlisted applicants.
The evaluation report identifies the preferred applicant but does not name the evaluator.
The committee secretary asks:
Who recommended the applicant?
This asks for the evaluator’s identity.
If the committee already knows the evaluator but needs to establish which person was recommended, the question changes:
Who did the evaluator recommend?
Now the missing information is the person receiving the recommendation.
The secretary could be more specific:
Which of the two applicants did the evaluator recommend?
This makes clear that the choice is between two known applicants.
Finally, the committee chair might report the question during a meeting:
The director asked which applicant the evaluator had recommended.
The information is now expressed through an embedded question rather than a direct one.
Each form fits a different information need.
When a Grammatical Question Is Too Broad
Suppose a publishing manager has two manuscripts and needs to know which one received final approval.
The manager asks:
What was approved?
The question is grammatical, but it could refer to a manuscript, budget, schedule, or another item.
A more precise question is:
Which of the two manuscripts was approved?
The second directs attention to the known options.
This does not make what grammatically wrong. It makes which more suitable for the intended question.
Likewise, Who signed the document? asks for the person who signed it, while Whose is this document? asks about ownership or association. Signing and owning a document are not necessarily the same thing.
Choosing an interrogative pronoun therefore involves more than selecting a grammatically possible word. The question should also make clear what information is being requested.
Check Your Understanding
Choose the appropriate form, identify its grammatical function, or revise the question.
1. Choose the appropriate pronoun.
Two proposed layouts are displayed on a screen.
(What / Which) would you prefer for the final brochure?
2. Identify the grammatical role.
Who identified the error in the financial statement?
Is who the subject or object of identified?
3. Choose the natural everyday form.
(Who / Whom) did you speak to about the revised deadline?
4. Complete the question with a pronoun expressing possession.
Several identical umbrellas have been left in a meeting room. A colleague points to one and asks:
______ is that one?
5. Identify the word’s function.
Which candidate received the highest score?
Is which a pronoun or a determiner?
6. Correct the embedded question.
The director asked what did the auditors discover.
7. Choose the appropriate verb.
The organizer wants to know which members of a group have withdrawn; more than one may have done so.
Which of the applicants (has / have) withdrawn?
8. Use the formal object form.
(Who / Whom) do you think the board appointed as chair?
9. Improve the question.
A publishing manager has two manuscripts and wants to know which one was approved. The manager asks:
What was approved?
Rewrite the question so it clearly refers to the two manuscripts.
Answers
1. Which
Which is natural because the speaker is choosing between two identified layouts.
2. Subject
Who is the subject of identified. The question asks which person found the error.
3. Who
Who did you speak to? is the natural everyday form.
Whom is also grammatical, but more formal and less common in ordinary conversation.
4. Whose
Whose is that one?
Whose asks about possession and stands independently.
5. Determiner
Which identifies the noun candidate.
If the candidates were already understood, the question could instead be:
Which received the highest score?
Here, which stands independently as a pronoun.
6. Use embedded-question word order
The director asked what the auditors discovered.
The embedded clause uses ordinary subject-verb order without did before the auditors.
7. Have
Which of the applicants have withdrawn?
The context asks about a possible plural group, so plural agreement is appropriate.
If the speaker expected one applicant, Which of the applicants has withdrawn? would also be grammatical.
8. Whom
Whom do you think the board appointed as chair?
Whom is the formal object form because the board appointed that person.
Who is also standard in everyday English.
9. Identify the available choices
Which of the two manuscripts was approved?
The revised question identifies the two manuscripts as the relevant options, rather than asking an open-ended question about what received approval.
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