Which is correct? “I don’t like who I’ve become.” “I don’t like whom I’ve become.”
Who, I believe. You’re replacing “the person,” as in “I don’t like the person I’ve become.”
Whom is used as the object of a preposition.
A handy trick I learned for differentiating between who/whom is to substitute the words he/him into the sentence. IOW:
I don’t like who I’ve become.
I don’t like he (I’ve become).
I don’t like whom I’ve become.
I don’t like him (I’ve become).
Get it? In other words, if you insert the word “he” into the clause and it doesn’t make sense, use “whom.” And vice-versa.
That’s not consistent.
I don’t know him is right, but I don’t know whom loves her. is wrong, and vice versa.
You should only look at the last part of the clause:
he loves her -> who loves her -> I don’t know who loves her.
So, in the given example, a better way of thinking about it is:
I have become him -> I have become whom -> I don’t like whom I have become.
And cher, “whom” is not just the object of a preposition; it’s also the object of a verb, just like “him”.
Thanks, matt, that’s clearer. Now can you do “which” and “that?” They drive me nuts.
The major problem is one of sound, not grammar. I’m almost certain that Matt etc. are correct in that “whom” is correct, but “I don’t like whom I’ve become” will throw your readers off. You’d be much better off going with “I don’t like the man/woman I’ve become.”
Just my opinion.
LL
The issue is not sound. It is grammar.
The case of a relative pronoun (who, whom, whose) is determined by the function it serves in the sentence it modifies, not by its function in the sentence of the antecedent.
I don’t know whom I like is correct.
I don’t like who I’ve become is also correct, because become is a copulative verb (snicker snicker) just like the verb to be.
You wouldn’t say I don’t like whom I am just as you wouldn’t say I don’t like whom I’ve become.
MR
I don’t know if HE can, but I can.
“that” is used to differentiate among several things,e.g.:
“I’m fixing the lawnmower that won’t start.” (I’m fixing the broken one and not any of the other lawnmowers around.)
“Which” is used to add information about the only thing in question, e.g.:
“I’m fixing the lawnmower, which won’t start.” (adds information about the only lawnmower around.)
Notice the comma before “which” in the second example… you can hear the pause when you say this sentence out loud, which is one way to know whether to use “which” or “that”… a phrase using “which” is always set off by a comma (I’m not talking about sentences like “Which one of us is sober enough to drive?”…just restrictive clauses.)
Hope that helps.
…but there is an easier explanation, I guess.
Which emphasizes the antecedent.
That emphasizes the following dependent clause.
The difference in nuance can be trivial. I pick the one that comes more naturally into mind. If I try and think too hard about which pronoun to use, I drive myself insane.
MR
“Ask the Grammar Harpy” addresses these questions. In MPSIMS. Died a while ago, but resurrect if you like.
Non-grammatical solution, but almost always correct:
When in doubt, use “that.” When it just sounds wrong, substitute “which,” especially after a comma.
(This based on the fact that in common usage “which” is more likely to incorrectly replace “that,” rather than vice versa: “that” will always sound wrong in place of a proper “which,” but the reverse is rarely true.)
Also, I often use a “which” to avoid too many “thats” in a sentence, though “that” might be perfectly correct:
She insisted that the bullet hole which stared at me from between her eyes was a figment of my imagination.
(An awkward construction I’d probably smoothe out in practice, but just as an example of the principle at hand.)
My suggestion:
“She insisted that the bullet hole staring at me from between her eyes was a figment of my imagination.”
So you were squicking her?
A. Thanks, but as I said, I was aware that it was an awkward construction. It was hastily conjured simply as an example.
B. Stylistically (as opposed to grammatically) I avoid gerunds as inelegant. Very personal style issue; no need to debate it here.
MR: Thank you! I knew I was missing something. Of course, become and be are the same class of verb. I need to go study up 
LL
L:
Cool. We can just agree to disagree. I learned the bit with gerunds etc b/c I found that on SAT questions the answer with the gerund was correct 75 percent of the time.
FWIW, in 90 percent of writing it won’t matter. The other 10 percent whoever’s reading it usually has a stick up his or her ass or it’s for an English class.
one thing I’ve found in the years of being in the newspaper business is that there is ALWAYS an exception to the rule, and ALWAYS an exception to the Exception…
“There’s an exception to every rule, except this one.”