Who vs. Whom: When to use Which in that Confusing Language called English.

I once asked a colleague to help me decide between using who and whom in a sentence, and got this long-winded, erudite, off-color, and witty reply. If you are easily offended please read no further. It's published here with his permission. I've removed his name to protect him, even though he's not innocent:

You, asking me, for grammatical advice? Could it be? Could I be so fortunate? OK: whom is used wherever you use the word in the objective case, and who is used wherever you use the word in the subjective case.

To wit:

Sam is going to town. (Sam = Subject). Thus: Who is going to town?
Sam is going to town with Ollie. (Ollie = object, in this case, the object of a preposition). Thus: Who is going to town with whom?
Sam is going to insult Ollie. (Ollie = Direct Object). Who is going to insult whom?

The heuristic is: use WHO at the beginning of a sentence and WHOM in the middle or at the end because subjects are often at the beginning and objects often middle to end. But this is a rough guide, as English allows a clause to begin in the middle of another clause already in progress. It's rude grammar, you could say. To wit, the heuristic-busting exception:

Sam did not know who was going to town.

First phrase: Sam (subject) did (verb) not know (verb). . .
Second phrase: . . . who (subject of the second clause) was (verb) going (verb) to (preposition) town (object of the preposition). So here a WHO in the subjective case has sneaked into the middle of a sentence, where you might suspect an OBJECT to be. Here is the heuristic conforming version:

Sam did not know for whom the bell tolled. (As it turned out, the bell tolled for Hemingway.)

But that's a dead giveaway because a WHOM is [almost] always used after a preposition (for, by, because, to, after, with, etcetera . . . ).

But what about:

Sam is going to give the ticket to [whoever/whomever] is going to town.

If the "who" is the object of the preposition, then it is whoMever. BUT, if the "who" is the subject of the following clause, then it is whOever! So which is it?

I don't know!

But my guess is it is whOever because unless the word is whOever (subjective), you end up with the second clause having no subject, and clauses or sentences without subjects are very, very rude. To wit:

F**k!

... which is a rude sentence indeed, being a verb with no subject. Although it is implied that either the speaker (who?) or the spoken to (whom?) is the subject of the above rudity. (Who f**ked? F**king whom? Who was f**king whom? Which reminds me of a great limerick, which manages to be subversively politically incorrect while at the same time being gramatically correct. I leave it to you to determine which is more important:

A [male homosexual] who lived in Cancun
Invited a [female homosexual] up to his room.
The rest of the night
Was spend in a fight
About who would do what to whom.)

Here's a better example:

Gone to town.

Now that's illegal. WHO, dang it, has gone to town? You can't have sentences without subjects unless they're implied. So, by putting whOever into the subjetive case as the subject for the second clause, everybody's happy. This is because a clause without an object is in less need than a clause without a subject. From each according to his verbosity to each according to his need. The ultimate redistribution of wealth. So you see, grammar is communistic. And grammarians are commie pinko bastards all.