Understanding Whom vs Who: A Grammar Guide

The Basic Difference Between Who and Whom

Understanding the difference between "who" and "whom" comes down to one simple concept: whether the word is acting as a subject or an object in a sentence. This distinction matters in formal writing, professional communication, and academic contexts. Many people find this rule confusing because spoken English has largely abandoned the distinction, but written English—especially in business, education, and publishing—still values this grammatical accuracy.

The word "who" functions as a subject. A subject is the person or thing performing an action. Think of "who" as performing something. For example, "Who called the office?" In this sentence, "who" is the subject performing the action of calling. The person asking this question wants to know which person made the call. You can test whether you need "who" by substituting the word "he" or "she." If the sentence still makes sense with "he" or "she," then "who" is correct.

The word "whom" functions as an object. An object receives the action or comes after a preposition. "Whom" refers to the person being acted upon. For example, "Whom did you call?" Here, "whom" is the object receiving the action of being called. You can test whether you need "whom" by substituting "him" or "her." If the sentence works with "him" or "her," then "whom" is correct. Notice that both "whom" and "him" end in the letter "m"—this can serve as a helpful memory device.

A practical takeaway: When you encounter "who/whom," pause and ask yourself, "Is this person doing something (subject) or having something done to them (object)?" If doing something, use "who." If having something done to them, use "whom." This simple test works in nearly all situations and will guide you toward the correct choice.

Who as the Subject of a Sentence

When "who" acts as the subject, it means the word refers to the person performing the main action in the sentence. Subjects are essential parts of every sentence—they tell us who or what is doing something. Understanding this role helps you recognize when "who" is the right choice. In professional contexts, using "who" correctly as a subject shows attention to detail and command of language.

Consider these examples: "Who wrote this report?" The subject here is "who," and this word refers to the person who performed the writing action. The sentence structure is straightforward: [Subject "who"] + [verb "wrote"] + [object "report"]. Another example: "Who will attend the meeting tomorrow?" Here, "who" is the subject, and the person asking wants to know which person will be present at the meeting. The action being performed is attending, and the subject performing it is "who."

Here are additional examples showing "who" in subject position:

• "Who discovered penicillin?" (Answer: Alexander Fleming—"he" discovered it, so "who" is correct)
• "Who manages the marketing department?" (Answer: Sarah manages it—"she" manages it, so "who" is correct)
• "Who sent you that email?" (Answer: Tom sent it—"he" sent it, so "who" is correct)
• "Who will be presenting at the conference?" (Answer: Dr. Johnson will—"she" will, so "who" is correct)
• "Who broke the window?" (Answer: The children did—"they" did it, so "who" is correct)

Notice the test method works every time: Can you substitute "he," "she," "they," or another subject pronoun? If yes, "who" is correct. A practical takeaway: When writing or speaking about the person performing an action, use "who." This is the most common form in everyday communication, which is why you'll see "who" used more frequently than "whom" in most texts.

Whom as the Object of a Sentence

When "whom" acts as an object, the person it refers to is receiving an action rather than performing one. Objects receive actions, and they can appear in different positions within a sentence. Understanding object positions helps you spot when "whom" is needed. In formal writing and professional documents, using "whom" correctly demonstrates grammatical sophistication and precision.

The most straightforward examples involve "whom" as a direct object. A direct object receives the action of the verb directly. Consider: "Whom did you interview?" The person being interviewed is the object receiving the action. You can verify this by substituting "him" or "her": "Did you interview him?" Yes, this works, so "whom" is correct. Another example: "Whom should we contact about this issue?" The person being contacted is the object. Test it: "Should we contact him about this issue?" Yes, so "whom" is correct.

Here are additional examples showing "whom" in object position:

• "Whom did the company hire?" (Answer: They hired her—"her" is an object pronoun, so "whom" is correct)
• "To whom should I send this document?" (Answer: Send it to him—"him" is an object pronoun, so "whom" is correct)
• "Whom will you choose for the position?" (Answer: I will choose her—"her" is an object pronoun, so "whom" is correct)
• "With whom did you have lunch?" (Answer: I had lunch with him—"him" is an object pronoun, so "whom" is correct)
• "Whom are you inviting to the event?" (Answer: I'm inviting them—"them" is an object pronoun, so "whom" is correct)

"Whom" also appears as the object of a preposition. Prepositions are small words that show relationships, like "to," "with," "for," "from," and "about." When a preposition comes before "who/whom," the answer should be "whom." Examples: "For whom did you buy the gift?" "From whom did you receive this information?" "About whom were you speaking?" A practical takeaway: When the person is receiving an action or following a preposition, use "whom." If substituting "him" or "her" works, "whom" is correct.

The Substitution Method: Your Most Reliable Test

The substitution method is the single most reliable technique for choosing between "who" and "whom." This method works consistently because it relies on patterns you likely already understand, even if you haven't thought about them consciously. Using this technique eliminates guesswork and builds confidence in your writing decisions. Professional writers, editors, and educators rely on this method because of its accuracy.

Here's how the substitution method works: First, identify the "who/whom" phrase in your sentence. Second, remove it temporarily and replace it with a subject pronoun (he, she, they) or an object pronoun (him, her, them). Third, read the sentence with the substitution. Fourth, if the substitution is a subject pronoun and the sentence still makes sense, use "who." If the substitution is an object pronoun and the sentence makes sense, use "whom."

Let's walk through a detailed example. Consider the sentence: "The manager, who/whom we respect, gave us feedback." Remove the phrase: "The manager gave us feedback." Now substitute: Does "he gave us feedback" work? Yes. But wait—that's not quite right because "he" appears in a different role here. Instead, look at the original structure: "we respect who/whom." Substitute into this phrase: "we respect him" or "we respect he"? The first one works: "we respect him." Since "him" is an object pronoun, "whom" is correct. The sentence should read: "The manager, whom we respect, gave us feedback."

Here are practice examples using the substitution method:

• Sentence: "Tell me who/whom you contacted." | Substitution: "you contacted him" or "you contacted he"? | Answer: "him" works, so use "whom." | Correct: "Tell me whom you contacted."
• Sentence: "I don't know who/whom will finish first." | Substitution: "he will finish first" or "him will finish first"? | Answer: "he" works, so use "who." | Correct