The word who functions as a relative pronoun and an interrogative pronoun used to identify or refer to a specific person or people. You'll encounter it when asking questions about individuals or when introducing a dependent clause that describes someone. It's a fundamental building block of English syntax, yet writers often confuse its boundaries with other pronouns like whom or which.
Understanding this word requires looking at how it anchors sentences. When you ask, "Who is speaking at the conference?", you're using it to demand the identity of a human subject. When you write, "The architect who designed this building won an award," you're using it to link a clause back to a person. It never applies to inanimate objects, animals without personal names, or abstract concepts. Let's break down the exact mechanics behind this versatile pronoun so you can use it with total confidence.
Subjective Case vs. Objective Case
English grammar relies heavily on cases to show how a pronoun functions within a sentence. Who is strictly a subjective pronoun. That means it acts as the subject of a verb, performing the action of the clause it belongs to. If you can substitute he, she, or they into the phrase, you need who.
For example, consider the sentence: "Who left the front door open?" You can answer this by saying, "He left the front door open." Because he is a subject pronoun, who is correct. Additional information regarding the matter are covered by Associated Press.
Writers frequently stumble when choosing between who and whom because they don't look closely enough at the immediate clause. Whom is the objective counterpart. It receives the action or follows a preposition, just like him, her, or them.
- Isolate the clause containing the pronoun.
- Substitute a personal pronoun (he/him or she/her).
- If he or she fits, use who.
- If him or her fits, use whom.
Let's test this rule on a tricky sentence: "Give the assignment to who or whom?" Strip away the prepositional context for a second and look at the clause. If you answer, "Give it to him", you need whom. If you say, "Give it to he", it sounds wrong. Therefore, prepositions demand the objective case in formal writing, though modern conversational English often softens this distinction. You can read more about standard pronoun guidelines on the Merriam-Webster Dictionary website.
Using Who in Direct and Indirect Questions
Interrogative usage represents the most common encounter most people have with this word. You use it to form direct questions where the identity of a person is unknown.
- Who brought the prototype to the meeting?
- Who is managing the new regional office?
- Who signed off on the budget adjustments?
In each instance, the pronoun stands in for the missing person who executed the verb. Notice how the verb immediately follows the pronoun in these simple direct questions.
Indirect questions introduce a layer of embedding, which causes confusion for many writers. Consider this sentence: "I want to know who authored the report." The phrase "who authored the report" is a noun clause acting as the object of the verb want. Even though the entire sentence is a statement, the inner clause still treats who as the subject of authored.
A common mistake is turning indirect questions into awkward statements by misplacing the pronoun or adding unnecessary auxiliary verbs. Keep the inner clause straightforward. Don't write, "I want to know whom authored the report," because the author is performing the action, requiring the subjective case.
Relative Clauses and Antecedents
Beyond asking questions, who connects dependent clauses to human antecedents. An antecedent is the noun that the pronoun refers back to.
If your antecedent is a person, who is your go-to relative pronoun. For instance: "The technician who repaired the server deserves recognition." Here, technician is the human antecedent, and the clause "who repaired the server" modifies it.
You should never use who for non-human entities. Writers sometimes make the mistake of writing, "The corporation who acquired our startup," but corporations are legal entities, not individual people. For companies, animals, or objects, use that or which.
- Incorrect: The software who processed our payroll crashed.
- Correct: The software that processed our payroll crashed.
- Correct: The accountant who processed our payroll caught the error.
Getting this distinction right separates amateur prose from polished, professional writing. You can find further linguistic breakdowns on The Chicago Manual of Style Online for detailed syntax rules.
Common Mistakes to Avoid
Even experienced writers slip up when complex sentence structures obscure the pronoun's role. Let's look at the traps you need to dodge.
Overcorrecting to Whom
Many writers think whom sounds smarter, so they drop it into slots where who actually belongs. This phenomenon is called hypercorrection.
- Incorrect: Give the award to whom deserves it most.
- Correct: Give the award to who deserves it most.
Why is who correct here? Because the entire clause "who deserves it most" acts as the object of the preposition to, but within that dependent clause, who is the subject of the verb deserves. You must always look inside the local clause to determine case, rather than just looking at the word that precedes it.
Confusing Who and That
Another frequent error involves replacing who with that when referring to specific people. While that can sometimes apply to people in casual speech, formal writing demands who.
- Casual: The employee that hit their sales target gets a bonus.
- Formal: The employee who hit their sales target gets a bonus.
Using who restores a human element to your sentence, making it sound more respectful and precise.
Frequently Asked Questions
Can who be used as a plural pronoun?
Yes. Who has no grammatical number on its own; it takes its number from its antecedent. In the sentence, "The students who study hard pass the exam," the verb study is plural because students is plural.
Is whom disappearing from modern English?
It's fading in casual conversation, but it remains active in formal writing and after prepositions. If a sentence feels awkward with whom, you can often restructure it to avoid the pronoun entirely.
How do I remember the difference between who and whom?
Think of who as matching he or she, and whom as matching him or her. If you can answer the question with m, use the word with m.
Can animals be referred to as who?
Usually, animals are referred to as that or which. However, if an animal has a proper name and is treated as a family member, writers sometimes use who stylistically, though traditional grammarians prefer that.
