Tip: If you're serious about improving your writing, one of the best ways is to improve your vocabulary — not so you know how to use big words, but so you can choose the right word at the right time to convey your meaning precisely and simply. To improve your vocabulary, we highly recommend you try the popular vocabulary-improvement software called Ultimate Vocabulary. Click Ultimate Vocabulary for details.*
First of all, hop on over to my article on Simple Sentences to get a good idea of what is meant by the subject and object of a sentence. I'll wait for you here ...
... OK ... now that you're back, it won't take us long to finish this topic!
The grammatical definitions (if you must):
Who is a relative pronoun, used to introduce a clause that provides further information about a person or people previously mentioned. It is used as the subject of a sentence.
Here are a couple of quick examples to illustrate:
Whom did Ruby tickle?
Juliet was the first chef who cooked sardines in chocolate.
The he/him trick
Here's a trick to help you figure out the correct usage. Rephrase the sentence so that he/him fits in place of who/whom. If "he" (a subject) fits the sense, then use "who", and if "him" (an object) fits, then use "whom":
1. Who/whom made that mess?
He made that mess (not Him made that mess), so "Who" is correct (He = Who).
Who made that mess? is correct.
2. For who/whom should I work?
Should I work for him (not Should I work for he), so "Whom" is correct (Him = Whom).
For whom should I work? is correct
3. To who/whom do I send this?
Do I send this to him? (Not Do I send this to he?), so "Whom" is correct.
To whom do I send this? is correct
Whom is one of those words that is waning in popularity, and rarely used nowadays in contemporary English. It can sound rather formal and pretentious, so use it with care. You can answer the phone with the grammatically correct "Whom am I speaking to?", but "Who am I speaking to?" is quite acceptable as well and less stuffy. "To whom it may concern" is probably its most common usage.
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