Who or Whom: How to Know Which One to Use

Who is usually the subject of a sentence, while whom is traditionally used as the object of a verb or preposition.

Imagine you are writing an important email. You type, “Who should I contact?” Then you stop. Maybe “Whom should I contact?” sounds more professional. But which one is actually right?

I faced this same question while checking students’ writing. Many students knew the words who and whom, but they were never sure when to use each one. Some used whom whenever they wanted to sound formal. Others avoided it completely and used who everywhere.

The real problem is that the rule is often taught in a way that feels harder than it is.

Once you look at the role of the person in the sentence, the difference becomes much clearer. There is also a modern twist: everyday English often uses who in places where traditional grammar uses whom.

So you may see:

• Who called you?
• Whom did you call?
• Who did you call?

The first two show the traditional distinction. The third is very common in modern English.

In this guide, you will learn a simple way to tell them apart, see how native speakers use them, and understand which form fits formal writing, conversation, emails, and everyday questions.

Whom or Who: The Basic Rule

Use who when the person is the subject.

Who wrote this message?

The person is doing the writing.

Use whom when the person is traditionally the object.

Whom did you invite?

The person receives the action of invite.

The He/Him Test

When you are unsure, turn the question into a statement.

Who called you?
→ He called you.

So use who.

Whom did you call?
→ You called him.

So traditional grammar uses whom.

The shortcut is:

he / she → who
him / her → whom

This also works with:

they → who
them → whom

Where Did Who and Whom Come From?

Who and whom are related forms that developed from older English pronouns.

English once had a stronger case system. Pronouns changed form depending on their role in a sentence. Some of these differences survived even after many other case forms disappeared.

That is why English still has pairs such as:

• he → him
• she → her
• they → them
• who → whom

Over time, everyday English became less dependent on whom. Today, it remains common in formal writing but is much less common in casual speech.

Who or Whom After a Preposition?

Traditional grammar uses whom after a preposition.

Examples:

• To whom did you send the letter?
• With whom did you travel?
• For whom is this gift?
• From whom did you receive the message?

In everyday English, speakers often put the preposition at the end and use who:

• Who did you send the letter to?
• Who did you travel with?
• Who is this gift for?
• Who did you receive the message from?

The first style is more formal. The second is common in conversation.

A familiar formal phrase is:

To whom it may concern

This is still widely used in formal letters and documents.

Who vs. Whom: Comparison Table

Term	Meaning	Region/Context	Best Used When
Who	Person doing an action	Standard and everyday English	The person is the subject
Whom	Person receiving an action	Formal/traditional English	The person is the object
Who	Modern object form	Informal English	Casual questions
Whom	Formal object form	Formal English	Official or careful writing
Who	Common after a final preposition	Conversation	Natural speech
Whom	Traditional form after a preposition	Formal writing	Structures such as “to whom”

When Is Who More Natural?

Who is the normal choice when the person is the subject:

• Who opened the door?
• Who wrote the report?
• Who knows the answer?
• Who wants to come with us?

It is also very common in everyday object questions:

Who did you meet?

Traditional grammar may prefer:

Whom did you meet?

Both forms are familiar, but the first is more natural in casual conversation.

When Is Whom Useful?

Whom is most useful when you want to follow traditional grammar or maintain a formal tone.

Examples:

• Whom did the committee appoint?
• Whom should I contact?
• To whom should I send the application?
• With whom did you discuss the matter?

However, do not choose whom just because it sounds formal.

For example:

Whom wrote the report? ❌

The person is doing the action, so the correct form is:

Who wrote the report? ✅

Common Mistakes with Who and Whom

Using Whom as the Subject

❌ Whom called you?
✅ Who called you?

The person is the one performing the action.

Thinking Who Is Always Informal or Wrong

❌ Assuming Who did you invite? is simply incorrect.

It is widely used in modern English. Whom did you invite? follows the traditional object rule and may suit formal writing better.

Using Whom Everywhere

❌ Whom is coming to dinner?
✅ Who is coming to dinner?

The person is the subject, so who is required.

Confusing Who’s and Whose

Who’s means who is or who has.

Who’s coming with us?

Whose shows possession.

Whose phone is this?

Neither word is a form of whom.

Whom or Who in Real-World Writing

Professional Email

Could you please let me know whom I should contact about this issue?

This version has a formal tone.

A more conversational version is:

Could you please let me know who I should contact about this issue?

News Article

Who will lead the new project?

Here, who is the subject of will lead.

Another possible sentence is:

Whom did the committee appoint?

Here, whom is the traditional object form.

Social Media Post

Who else is watching this tonight?

The conversational tone makes who the natural choice.

Formal Document

To whom it may concern

This is a standard formal expression.

How English Uses Who and Whom Today

The search intent behind “whom or who” is mainly informational. People usually want to check grammar, understand the difference, or decide which form fits a sentence.

Modern usage has made the distinction less strict in everyday English.

Whom remains useful in:

• formal letters
• official documents
• academic or careful writing
• traditional grammar exercises
• expressions such as to whom it may concern

Who is common in:

• everyday conversation
• casual emails
• social media
• informal questions
• many modern object constructions

The practical lesson is simple: learn the traditional rule, then consider the context.

FAQs About Whom or Who

What does “whom or who” mean?

They are pronouns used for people. Who normally acts as the subject, while whom traditionally acts as the object.

How can I quickly choose between who and whom?

Use the he/him test. If he fits, choose who. If him or her fits, traditional grammar uses whom.

Is “Who did you call?” correct?

Yes. It is very common in modern English, especially in conversation. Traditional grammar prefers “Whom did you call?”

Is whom still correct English?

Yes. Whom remains a standard English form and is especially useful in formal writing and after prepositions.

Which is better for formal writing?

When the pronoun is an object, whom can fit a formal or traditional style. For example, “To whom should I address the letter?”

Can who replace whom?

In many modern and informal contexts, yes. English speakers commonly use who in object questions such as “Who did you meet?”

Is “to whom it may concern” still used?

Yes. It remains a standard formal expression, especially in letters, applications, and official documents.

Conclusion

The difference between whom or who is easier when you focus on the person’s role.

Use who for the subject. Use whom for the object when following traditional grammar. The he/him test can help you check difficult sentences quickly.

Modern English also gives you some flexibility. Who is very common in everyday object questions, while whom remains useful in formal writing and fixed expressions.

The goal is not to make every sentence sound formal. It is to choose a form that is grammatically clear and appropriate for your audience.

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