Many English speakers do not know the difference between who and whom. In some places, it hardly matters, because using who when you should use whom is. Use this he/him method to decide whether who or whom is correct: he = who him = whom. Examples: Who/Whom wrote the letter? He wrote the letter. Therefore. Like whom, the pronoun him ends with the letter M. When you're trying to decide whether to use who or whom, ask yourself if the hypothetical.