Who vs Whom- Overthinking or Bad Tricks?

I get confused about the “tricks” we are supposed to use to figure out the right word.

“Don’t forget about the commissions you’ll be earning coming from those who you referred.”

I realize “you referred them,” so “whom“ would make sense.

But, couldn’t I also argue that “they were who you referred”? So, “who” would be correct?


As John Lawler says in his comment, "whom" can always be replaced by "who".

I would go further, and suggest that if you're saying "whom", you need to think carefully about whether that's appropriate for your audience. It's probably not.