“Who” and “whoever” are so-called “subjective pronouns,” whereas “whom” and “whomever” are used for objective cases. Usually, we use those words in combination with a question or a relative clause about a person. Although the usage of “who” and “whom” is quite simple to most people, some may still stumble upon some difficulties. 

With this short guide, it’ll be much easier for you to decide when to use “who” or “whom” correctly in the future!

Who

“Who” (as well as “whoever”) always acts as a subject to a verb. Meaning, the person (subject) is the one doing the action. You can easily double-check the correct usage if you can replace the word with “he,” “she,” a person’s name, or another subject pronoun. There are two cases where you’d use “who:”

Questions:

You can use “who” as an interrogative pronoun at the beginning of a question or for indirect questions and statements. 

Who asked for my number?
(He asked for my number.)

Who called yesterday night when everybody was sleeping?
(Carl called yesterday.)

Who is the manager here?
(She is the manager.)

Who in their right mind would do something that stupid?
(They would do something that stupid.)

Who on earth would do a thing like this to Michael?
(They would do such a thing.)

Relative Clauses:

As mentioned above, “who” also works as a relative pronoun to introduce a relative clause about a person.

The person who is responsible for this mess should come forward.
(He is responsible for this mess.)

It was Jim who called yesterday.
(Jim called yesterday.)

Pete, who works in customer support, is on holiday this week.
(Pete works in customer support.)

We all know who did this to them.
(Jimmy did this to them.)

This book is about a man who tries to find the meaning of life.
(The book’s protagonist tries to find the meaning of life.)

💡 “who” acts as a subject to a verb

💡 double-check the correct usage by replacing it with “he/she/they/name”

Whom

“Whom” (and “whomever”) always takes the part of the “object case” in a sentence. Meaning, the person (“whom”) is the one receiving the action from the sentence’s “subject.” Similar to “who,” you can double-check the correct usage by replacing “whom” with “him,” “her,” “them,” or another object pronoun. In general, however, we use “whom” and “whomever” rather seldom, and if we use it, it’s more common in writing than speaking.

In Combination with Prepositions:

“To,” “for,” “by” are each one of the most common prepositions that are combined with “whom.” Depending on the formal writing style, the preposition stands either right before the object “whom” or is “left hanging” at the end of the sentence.

To whom did she speak?
(She spoke to him.)

Whom did Peter work for?
(Peter worked for him.)

It depends on by whom the products will be tested.
(The products are tested by the partner company.)

He never told her where he went and with whom.
(He went with them.)

It’s up to whom the task is given.
(The task is assigned to her.)

Relative /Subordinate Clauses:

“Whom” and “whomever” may also act as a relative object pronoun, meaning that it refers to a previously mentioned subject or noun phrase.

She recently gave birth to a boy whom she named Steven.
(She named him Steven.)

My dog barked at a man whom I’ve never met before.
(My dog barked at him.)

They need to figure out who attacked whom.
(The man in the blue shirt attacked him.)

💡 “whom” acts as an object and receives the subject’s action

💡 double-check the correct usage by replacing it with “him/her/them”