Some GMAT sentence correction questions test not only for the accepted rules of grammar but also for the specific preferred style of the GMAT. Luckily, “who” vs. “whom,” is not one of those issues; this is a pretty straightforward issue, and is usually not tested in a complicated way. However, since even the most knowledgeable and educated writers sometimes misuse “who” and “whom,” it’s worth reviewing a couple of rules that can help guide you in determining the correct usage of these pronouns.
1. If someone were to ask a question about the sentence, would the answer be “him/her/them” or “he/she/they”?
This is probably the most effective way to remember the difference between “whom” and “who,” and most of the time, this will be enough to help you answer correctly. If a question about the action being described would be answered with “him,” “her,” or “them,” then the correct form is “whom.” If a question about the action being described would be answered with “he,” “she,” or “they,” then the correct form is “who.” Just remember this: the words with M’s at the end go together. They = Who, and Them = Whom. Here’s a basic sentence addressing this issue:
The Dalmation is a high-strung, energetic dog, and has historically been associated with firefighters, who/whom originally used the animal to guard and guide the horses that pulled fire-carts.
In this sentence, you can determine the correct answer by asking yourself about the action being described: “Who was associated with Dalmations?” And then answer that question with the correct pronoun: “They were.” Since “they” is appropriate here, we use “who” in the sentence. Let’s try the same approach on another sentence.
If the delivery driver doesn’t arrive this afternoon, I will have to call to call whoever/whomever I can find from the shipping division.
Now ask yourself: “Which people am I supposed to call?” And answer with a pronoun: “I am supposed to call them.” Therefore, we use “whomever” in the sentence.
2. Within a sentence, a verb that has a tense must have a subject; that subject must be in the nominative case.
Whenever a verb has a tense, it has to have a subject, and therefore the word to use in that situation will be the subjective pronoun “who” or “whoever.”
For example:
When the fundraiser was over, my neighbors said that they had given money to whoever/whomever was collecting donations.
There are several verbs with tenses in this sentence, and we can check them all for correctness: first, we have “was over,” and the subject is “fundraiser”. Then, we have “said,” and there the subject is “my neighbors.” We also have the verb “had given,” and its subject, “they,” and finally, “was collecting,” the subject of which would be “he” or “she,” because the correct phrase would be “he/she was collecting.” Therefore, “whoever” is correct. This one may be a little confusing, because we could ask a question, as described above, and get the opposite answer: “Who did they give money to?” “They gave money to him.” But that leaves the verb “was collecting” without a subject. While rule 1 above will usually get you the correct answer, because “whom” vs. “who” is usually tested in the simpler fashion seen there, if rule 1 and rule 2 produce different answers, you’re probably asking the wrong question. The key here is to remember that if rule 2 is applicable, it trumps rule 1.
Now let’s put it all together with a GMAT-style sentence:
When Walter asked the librarian for help, he was told that the archives hold documents from several authors, many of whom are no longer well-known but who were well-respected by their peers.
We have two “whom” vs. “who” issues in this sentence, and both can be answered using rules 1 and 2 above. For the first instance, “many of whom are no longer well known…” we can ask, “How many authors are no longer well known?” And the answer is, “Many of them.” Thus, “whom” is correct in the sentence. And then we examine the verb “were,” which is in the past tense. The subject of that verb would be “they,” as in “they were,” which would make the correct pronoun “who.” In this sentence, then, both of those pronouns are correctly used.
Even experienced grammarians sometimes differ on their preferred usages of “whom” and “who,” but these two rules should be enough to guide you through nearly all “whom” vs. “who” confusion in GMAT sentence corrections.