Who or whom? A CHEAT SHEAT?

Just remember the letter 'm'.

he = who
him = whom

Who/Whom wrote the letter?
He wrote the letter. Use who.

Who/Whom should I vote for?
Should I vote for him? Use whom.

My palms were sweaty listening to her.

Sometimes I use incorrect grammar on purpose, and my choice re who or whom then will depend not on the rules, but my sense of the formality in the sentence or paragraph I'm dealing with. In other words, once in a while 'whom' sounds too stuffy to me, re the conversation that is happening, so I will blithely use 'who'.

Me too. Horses for courses.

she = who
shim = whom

That's because,

“Whom” is a foreign word
Posted on January 25, 2011 | 5 Comments
Yet again I’ve been discussing with colleagues the question of where to use whom (and, more particularly, whomever – see I must disagree with whoever wrote that). One thing the issue shows us (in case we hadn’t noticed) is that whom and whomever are no longer parts of current English. By which I mean they are not part of the language that most English speakers speak – they are, effectively, foreign words, or at best part of a second language that the user may not be altogether comfortable with. Second language? Well, second dialect, and for the purposes of intuitive grasp of usage, that’s tantamount. Whom and whomever belong only to a more formal dialect that most English speakers are not comfortable with and do no use intuitively.

Although we have an intuitive grasp of the syntax of our native language that extends to intricacies far beyond most of our conscious analyses, that native language uses who in both subject and object positions. Whenever we go to use whom we are having to override a who, and we may grasp at straws to know exactly what we’re doing when we’re putting together our sentences.

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https://sesquiotic.wordpress.com/2011/01/25/whom-is-a-foreign-word/