The word “whom” has almost disappeared from modern English. However, it’s still very much alive and well on the GMAT, so we advise that students ensure they know the difference between "who" and "whom".
As with many grammar-related topics, Sentence Correction questions are where you can expect to see this issue come up.
Consider the following example from Economist GMAT Tutor's bank of practice questions:
Fernande Olivier was an artist who Picasso met in 1904 during the Rose Period, which is characterized by images of acrobats, harlequins, and other circus people .
As always, scan the original sentence for grammatical errors. You know that relative pronouns are an important area of GMAT Sentence Correction. The most important ones for our purposes are: who , which , that , whose and whom . Consider whether “who” is correct in this sentence.
Relative pronouns on the GMAT describe the noun or noun phrase immediately before them, in this case “artist”. The question you must ask yourself now is whether “artist” is the subject or the object of the relative clause , meaning the "doer" or "receiver" of the action. If it is the subject, use “who”. If it is the object, use “whom”. The relative clause is “who Picasso met…”. The easiest way to determine whether something is the subject or the object of a relative clause is to look at the verb , in this case “met”. Who did the meeting? Picasso. Thus, Picasso is the subject of the relative clause. Who was met? The artist. Therefore, the artist is the object of the relative clause. Therefore, we must use “whom” in this instance. Eliminate A and E.
B changes acrobats incorrectly to the adjective “acrobatic” and therefore breaks the parallelism of three nouns. Eliminate B.
C uses “whom” and has the original list in its correct parallel form. It seems correct, but let's check D to make sure.
D unnecessarily adds another verb: “shows”. Eliminate D, and C is our answer.
As you can see, it is worth investing time in becoming familiar with relative pronouns, as they play such a big part in GMAT Sentence Correction. The positive here is that the rules are not that complicated. By becoming an expert in these simple rules, you can even look forward to encountering them on test day.
This article first appeared here GMAT Grammar: Who vs Whom by Economist GMAT