“By Who” or “By Whom”: Meaning, Usage, and Examples for 2026

Understanding the difference between “By Who” or “By Whom” can feel confusing, especially when both phrases seem similar in everyday English. Many people wonder which one is grammatically correct and when it should be used.

The answer depends on the role of the word in a sentence. “Whom” is traditionally used as an object, while “who” is generally used as a subject. For example, formal English often prefers “By whom was this written?”

However, in modern and casual conversations, many people naturally say “By who was this written?” Even though it may sound more common, it is not always considered grammatically correct in formal writing. Learning the difference can help you write clearer emails, assignments, articles, and professional messages.

Quick Answer ⚡

“By whom” is grammatically correct because “whom” is the object of the preposition “by.” “By who” is technically incorrect in formal writing, but it’s so common in casual speech that most people won’t blink if you use it. Use “whom” for formal writing and “who” for everyday conversation.

Let’s break this down properly, though, because there’s a lot of useful stuff to learn here. 👇

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Why This Confuses So Many People

English has two words  who and whom  that both refer to a person, but they play different grammatical roles. Unlike other languages that keep this distinction crystal clear, English speakers have slowly started blending the two in casual speech.

Add prepositions like “by,” “to,” “with,” “from” into the mix, and things get even trickier. That’s exactly why phrases like “by who” vs “by whom” trip up so many writers, students, and even professionals. 📝

Here’s the core issue:

• Who is a subject pronoun (like “he,” “she,” “they”)Copy
• Whom is an object pronoun (like “him,” “her,” “them”)Copy

Once you get that distinction, this whole topic becomes much easier.

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“Who” vs “Whom”  The Real Meaning

🔹 Who (Subject Pronoun)

“Who” is used when the pronoun is doing the action in a sentence  it’s the subject.

Examples:

• Who wrote this report?Copy
• Who is coming to the party?Copy
• Who left the door open?Copy

In each case, “who” is performing the action (writing, coming, leaving).

🔹 Whom (Object Pronoun)

“Whom” is used when the pronoun is receiving the action, or when it follows a preposition like “by,” “to,” “with,” or “for.”

Examples:

• Whom did you invite? (You invited whom  whom receives the action)Copy
• To whom should I address this letter?Copy
• By whom was the decision made?Copy

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The “By Who” or “By Whom” Question, Specifically

When you add the preposition “by” before who/whom, grammar rules say the pronoun must be in the object form  which is “whom.”

That’s why:

✅ “By whom was this painting created?”  Correct (formal/written English) ⚠️ “By who was this painting created?”  Common in speech, but grammatically incorrect

Examples in Full Sentences

Sentence	Correct?	Notes
By whom was the letter written?	✅ Yes	Formal and grammatically correct
By who was the letter written?	⚠️ Informal	Common in casual speech, avoided in writing
The book was written by whom?	✅ Yes	Object of preposition “by”
Who is this gift by?	✅ Yes (informal)	“Who” at the end shifts tone casually
Whom is this gift by?	⚠️ Awkward	Grammatically valid but sounds stiff

Fun fact: Ending a sentence with a preposition (like “Who is this by?”) is completely acceptable in modern English, especially in casual and spoken contexts. 🗣️

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Simple Trick to Remember: The “Him” Test 🧠

Here’s the easiest mnemonic ever, and it works almost every time:

If you can replace the word with “him,” use “whom.” If you can replace it with “he,” use “who.”

Both “whom” and “him” end in -m  that’s your memory trick! 🔑

Try it yourself:

• “By ___ was this made?” → “By him” ✅ → so it’s “by whom”Copy
• “___ made this?” → “He made this” ✅ → so it’s “who”Copy

Question	Replace With	Answer
___ is calling?	He is calling	Who
To ___ should I speak?	Speak to him	Whom
By ___ was it approved?	Approved by him	Whom
___ approved it?	He approved it	Who

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Comparison Table: Who vs Whom vs By Whom

Term	Grammatical Role	Formal Usage	Example
Who	Subject pronoun	Common in speech & writing	Who called you?
Whom	Object pronoun	Formal writing, official docs	Whom did you call?
By who	Preposition + subject pronoun (technically incorrect)	Informal speech only	By who was this sent?
By whom	Preposition + object pronoun (correct)	Formal writing, legal/academic contexts	By whom was this sent?

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Common Mistakes People Make 🚫

1. Using “who” after every preposition  because “whom” sounds old-fashioned.
   
   • ❌ To who does this belong?Copy
   • ✅ To whom does this belong?Copy
2. Overcorrecting and using “whom” as a subject.
   
   • ❌ Whom is going to the meeting?Copy
   • ✅ Who is going to the meeting?Copy
3. Skipping “whom” entirely in formal writing, like resumes, legal contracts, or academic essays, where precision matters.
   Copy
4. Assuming “whom” is always more “proper.” It’s only correct when it’s grammatically the object  not just because it “sounds fancy.”
   Copy

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Real-Life Examples 🌍

📧 In Emails

“Could you confirm by whom this invoice was approved?” (Formal business tone  correct usage)

💬 In Texting/Social Media

“lol who was this even sent by 😂” (Totally normal in casual chats  “whom” would feel overly formal here)

📰 In News Writing

“Investigators are still trying to determine by whom the leak was orchestrated.” (Journalistic and formal writing tends to favor “whom.”)

🎓 In Academic Writing

“The theory was first proposed by whom many consider the father of modern linguistics.” (Academic papers strongly favor grammatical correctness.)

🗣️ In Everyday Speech

“Who was that call from?” (Almost nobody says “whom” out loud in casual conversation  and that’s completely fine!)

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British English vs American English 🇬🇧🇺🇸

Here’s an interesting nuance: both British and American English follow the same grammatical rule for “who” vs “whom.” However:

• British English tends to preserve “whom” slightly more in formal and journalistic writing (e.g., BBC News style guides).Copy
• American English is more relaxed, and “whom” is increasingly seen as old-fashioned even in semi-formal writing, especially in digital communication.Copy

In both dialects, “whom” is fading from everyday speech but still expected in:

• Legal documentsCopy
• Academic papersCopy
• Government and official communicationCopy
• Formal invitations (“To whom it may concern”)Copy

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Why “Whom” Is Slowly Disappearing 📉

Language evolves, and “whom” is a great example of a grammatical feature that’s fading from casual use. Linguists note that many English speakers now treat “who” as the default pronoun in almost all contexts, reserving “whom” only for:

• Set formal phrases (e.g., “To whom it may concern”)Copy
• Legal and academic writingCopy
• Careful, edited proseCopy

This doesn’t make “who” wrong in casual settings  English usage is shifting, and grammar rules often follow common usage over time. But if you’re writing something formal  a cover letter, a thesis, a contract  using “whom” correctly still matters. 📄

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FAQs: People Also Ask ❓

1. Is “by who” grammatically correct?

No, technically “by who” is incorrect because “who” is a subject pronoun, and prepositions like “by” require an object pronoun, which is “whom.” However, it’s widely used in casual speech.

2. Is it okay to use “by who” in emails?

In casual or internal emails, it’s usually fine. In formal business communication, legal writing, or official correspondence, “by whom” is the safer, more professional choice.

3. What is the easiest way to remember who vs whom?

Use the “him” test: if you can replace the word with “him,” use “whom” (both end in -m). If you can replace it with “he,” use “who.”

4. Why do people avoid using “whom” these days?

“Whom” sounds formal and old-fashioned to many speakers, so it’s naturally faded from casual speech, even though it remains correct in formal writing.

5. Is “whom” used in British English more than American English?

Yes, British English  especially in journalism and official writing  tends to retain “whom” a bit more than American English, though the grammatical rule is identical in both.

6. Can a sentence end with “who” instead of “whom”?

Yes! Ending a sentence with a preposition and “who” (e.g., “Who is this gift by?”) is common and accepted in modern, informal English.

7. Is it wrong to say “Whom is calling?”

Yes, this is incorrect. “Whom” should never be used as the subject of a sentence. The correct version is “Who is calling?”

8. Does “whom” still matter in modern English?

Yes, especially in formal, legal, academic, and professional writing. Even though it’s fading from casual speech, using it correctly still signals strong grammar skills.

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Final Takeaway 🎯

In conclusion, both “by who” and “by whom” relate to the person performing an action, but they are used differently. “By whom” is grammatically correct in formal English because “whom” functions as the object of a preposition. For example, “By whom was this book written?” However, “by who” is common in casual conversations and informal writing. Although it may sound natural, it is less formal. Understanding the difference helps you choose the right expression for each situation. Use “by whom” in formal contexts, while “by who” may appear in everyday speech.