English can be tricky, especially when it comes to formal grammar. One of the most common questions people face is whether to use “to who” or “to whom.” Even native speakers often pause before writing or speaking this phrase. The confusion usually arises because “who” and “whom” both refer to people, but they function differently in a sentence.
Understanding the difference is not just a matter of grammar it’s about sounding confident and professional, whether you’re writing an email, a letter, or even posting on social media. While some casual conversations allow more flexibility, in formal writing, using the correct form is essential.
This topic is particularly relevant for audiences in both the UK and the US. British English tends to preserve “whom” in formal contexts more often than American English, where people sometimes replace “whom” with “who” even in professional writing. Knowing the right usage helps you avoid mistakes in school, work, and everyday communication.
Quick Answer
The simple rule is: use “to whom” when referring to the object of a sentence, and “to who” is rarely correct in formal English.
- Correct: To whom should I address this letter?
- Incorrect: To who should I address this letter?
In casual speech, many native speakers say “to who,” and it is widely understood, especially in the US. However, for formal writing, interviews, academic work, or professional communication, “to whom” is always the safe choice.
Meaning of the Correct Form
“To whom” is the grammatically correct form when the pronoun is the object of a preposition, like “to,” “for,” or “with.”
- Prepositions in English usually require the object form of pronouns:
- Object form: him, her, them, whom
- Subject form: he, she, they, who
Examples in Sentences
British English:
- To whom did you give the invitation?
- This is the person to whom I was speaking yesterday.
- The teacher asked to whom the homework should be returned.
American English:
- To whom should I send this email?
- He didn’t know to whom he owed the apology.
- Can you tell me to whom this package belongs?
Notice that in formal writing, both UK and US English prefer “to whom.” The main difference is that Americans sometimes simplify it in speech: “Who should I send this to?” which is grammatically less formal but widely accepted in spoken English.
Meaning of the Incorrect Form
“To who” is considered incorrect in formal English because “who” is a subject pronoun, not an object pronoun. Using “who” after “to” technically breaks the grammatical rule.
Examples of Incorrect Usage
- To who did you send the letter? ❌
- Can you tell to who this belongs? ❌
- I don’t know to who I should speak. ❌
Although these sentences are often heard in casual conversation, they are grammatically incorrect in formal writing. In professional and academic contexts, using “to who” may make your writing look careless or informal.
Keyword Comparison / Key Differences
Here’s a quick table comparing “to who” vs “to whom”:
| Feature | To Who | To Whom |
| Pronoun type | Subject pronoun | Object pronoun |
| Grammatical correctness | Incorrect in formal English | Correct in formal English |
| Usage context | Informal speech | Formal writing and speech |
| British English | Rarely correct | Preferred in formal contexts |
| American English | Casual speech only | Standard in formal contexts |
| Example sentence | To who should I give this? ❌ | To whom should I give this? ✅ |
In short, “to whom” is always safe. “To who” might work in conversation, but it is best avoided in any formal setting.
Common Mistakes People Make
Even experienced writers and speakers sometimes mix up “who” and “whom.” Here are the most frequent mistakes and how to fix them:
- Confusing subject and object roles
- ❌ Who did you send the email to? (incorrect in formal writing)
- ✅ To whom did you send the email?
- Ending sentences with a preposition casually
- ❌ Who should I give this to? (informal)
- ✅ To whom should I give this? (formal)
- Using “who” after prepositions in emails and letters
- ❌ To who it may concern
- ✅ To whom it may concern
- Mixing spoken English habits with formal writing
In spoken American English, saying “Who should I send this to?” is natural and widely accepted. However, in British English formal writing, this is discouraged.
Correct Usage in Sentences
Here are multiple examples showing correct usage for both UK and US audiences:
Formal Written English
- To whom it may concern: Your application has been received.
- Please indicate to whom the funds should be transferred.
- I am writing to whom it may concern regarding this matter.
Professional Emails
- To whom should I address my inquiry regarding the job opening?
- Could you please clarify to whom this document should be submitted?
- I am unsure to whom the complaint should be directed.
Conversational English
Even in casual conversation, you can still technically use “to whom,” though it might sound formal:
- A: To whom are you speaking on the phone?
- B: Oh, just to Sarah.
American English often simplifies:
- Who should I send this to?
- Who did you give the gift to?
Both are widely understood, but remember, formal contexts still prefer “to whom.”
Tips to Remember the Correct Usage
Here are some practical tips and mnemonics to avoid mistakes:
- Object check trick:
- If the pronoun is the object of a preposition like to, for, with, by, use whom.
- Example: I spoke to whom? ✅
- Try substituting with him/her/them:
- Replace the pronoun with him, her, or them. If it makes sense, use whom.
- Example: I sent the email to him → To whom did I send the email? ✅
- Avoid ending with a preposition in formal writing:
- Instead of “Who are you talking to?” → To whom are you talking?
- UK vs US difference:
- British English: Prefer whom in formal writing.
- American English: “Who” is increasingly accepted in casual writing, but whom is still correct formally.
- Mnemonics:
- “Whom is the object, who is the actor.”
- Think: Actor = who, Recipient = whom.
FAQs
Q1: Can I use “to who” in emails?
- In formal emails, avoid it. Use “to whom.” Informally, many people in the US use “to who”, but it’s not standard grammar.
Q2: Is “whom” dying in American English?
- Yes, in spoken American English, “whom” is less common. People often use “who” instead, but it is still important in formal writing.
Q3: Can I end a sentence with “to whom”?
- Generally, no. In formal writing, avoid ending sentences with prepositions. Instead of “Who did you give it to?” → “To whom did you give it?”
Q4: How do I know whether to use “who” or “whom”?
- Use who for subjects, whom for objects. Quick test: Replace the pronoun with single one (subject) or him/her (object).
Q5: Examples in British English?
- To whom should I forward the application?
- The recipient to whom the letter was addressed was absent.
Q6: Examples in American English?
- To whom should I send this report?
- I asked to whom I should address the package.
Q7: Is “who to” acceptable?
- In casual speech: yes, it’s understood. In formal writing: no, always use “to whom.”
Conclusion
Choosing between “to who” and “to whom” may seem tricky, but the rule is simple: “whom” is the object of the preposition, while “who” is the subject. For formal writing, academic papers, professional emails, or letters, always use “to whom.”
Understanding this difference not only improves your grammar but also boosts your confidence in communication. Remember the simple tips: check the object role, substitute with him/her/them, and avoid ending sentences with prepositions in formal writing.
By mastering “to who or to whom,” you can write clearly, professionally, and correctly in both British and American English. Start applying these rules today, and your writing will stand out as precise and polished.
