‘According to the rules of formal grammar, who should be used in the subject position in a sentence, while whom should be used in the object position, and also after a preposition.’ (Oxford Dictionaries)
Use the he/him method.
- He = who
- Him = whom
- Who/Whom called the doctor? ‘He’ did. Who is correct.
- For who/whom are we voting? For ‘him’. Whom is correct.
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