
"Who" is the subject (does the action); "whom" is the object (receives the action).
"Who" is the subject pronoun for people. "Who called?" = which person made the call? Swap test: if "he" or "she" fits in the answer, use "who". "The person who called" = she called.
Who called me while I was in the meeting?
The woman who lives next door is a doctor.
Who is going to present the project tomorrow?
"Whom" is the object pronoun for people. "Whom did you call?" = which person did you call? Swap test: if "him" or "her" fits, use "whom". Always required after prepositions: "to whom", "with whom".
To whom should I address this letter?
The candidate whom the committee selected has ten years of experience.
With whom did she travel to the conference?
Common mistake
Trick to remember it
Substitution test: answer with "he/she" or "him/her." If the answer uses "he/she" = "who"; "him/her" = "whom." "Who/whom called?" → "he called" = "who." "Who/whom did you call?" → "I called him" = "whom."
Quick rule
Did you know?
WHOM is in the process of going extinct in spoken English. Linguists predict that in a few generations it will disappear from everyday speech and remain only in formal and legal texts, just as "thee" and "thou" (the Old English "you" singular) already did. For now, using it correctly in formal writing signals a high level of language mastery. The irony is that many native speakers hypercorrect and use WHOM where WHO belongs: "Whom shall I say is calling?", wrong; here WHOM is the subject of the subordinate clause, not the object, so WHO is correct.
Exercise 1 · Pick the right one
She's the friend _____ helped me move last year. I owe her a lot.
Exercise 2 · Pick the right one
The person to _____ I sent the email never replied.
Exercise 3 · Form the word
"That" introduces essential information; "which" introduces additional, non-essential information (set off by commas).
'Who\'s' contracts 'who is' or 'who has'; 'whose' asks or states who something belongs to.
'A' is used before consonant sounds; 'an' is used before vowel sounds.
'A lot of' works for countable and uncountable; 'many' only for countable; 'much' only for uncountable.
Bryan López
Founder of SpeakUP Academy