Who or Whom; Whoever or Whomever

Hello, Friends, 
Here is one of the most common errors I encounter: the confusion between who and whom or between whoever and whomever.
 This fun little “quiz.” will give you a sense of the challenge: Take the quiz first, review the discussion, and only then look at the answers. And with punctuation and grammar, remember: It is not enough to get the right answer, you need to know why!

Who or Whom? (Whom is on First?)

So, which is correct?
1. The man (who, whom) I saw walking up the lane has arrived.
2. The man (who, whom) I thought was coming has arrived.
3. She promised a copy to (whoever, whomever) wanted one.
4. She promised a copy to (whoever, whomever) he selected.

Choosing between who and whom or whoever and whomever seems to cause serious anxiety—and serious errors. And, practically speaking, I have noticed that the errors tilt in the whom, whomever direction. So, if in doubt, you are safer with the simpler who, whoever choice.

 
Back to Some Simple Grammar
Who and whoever are subject pronouns. Whom and whomever are object pronouns.

Subject Pronouns
Pronouns that serve as the subject of a sentence include these:
I, she, he, they, we, who, and whoever:
I did it. She did it. Who did it? I saw that she did it. I saw who did it. Whoever did it? 

Object Pronouns
Each object pronoun pairs up with a subject pronoun and serves as the object of a verb or a preposition: me, her, him, them, us, whom and whomever.
They saw me. They saw her. They saw him, them and us.
They saw whom? (Whom did they see?)

A Practical Tip
If he works in the sentence, use who or whoever. If him works in the sentence, use whom or whomever. (In fact, most errors occur with “stories within stories,” like in the sentences on the quiz.)

Answers

1. The man whom I saw walking has arrived.
    (The man has arrived. I saw him/whom walking.)

2. The man who I thought was coming has arrived.
     (I thought he/who was coming.)

3. She promised a copy to whoever wanted one.
    (He/whoever wanted one.)

4. She promised a copy to whomever he chose.
    (He chose him/whomever.)

Below are some interesting errors I have encountered in my reading and listening:
1. There will be time later to litigate whom who the true fools and fooled are (from a judge in the Los Angeles Superior Court).
2. Elizabeth, recalling this now, heard it as a prayer and repeated it to whomever whoever or whatever might be listening. (Anne Lamott, Crooked Little Heart, p. 261)
3. He never wanted to have children whom he said he found terrifying and boring in equal measure except for Leo, whom who he said didn't count as a child. (Anna Quindlin, Rise and Shine)
4. I played it for whomever whoever was around. (Senator Lamar Alexander on NPR)
 
I'd be happy to receive and share any “wonderful, awful” examples you encounter.