Would you post good links that explain when to use who and whom?

Where would you find a “good” link? Maybe a book on grammar?

If you can replace the word with “him”, you use “whom”.

^^. “him, her, them”= “whom
“He, she, they” = who

https://www.grammarly.com/blog/who-vs-whom-its-not-as-complicated-as-you-might-think/

^Good link. “Whom” is the objective form of the pronoun, like “him”, “me”, etc. “Who” is the nominative/subject form.

You can think of it in terms of replacing “whom” with “him”, but know that in relative and interrogative clauses, the word order is flipped, so you will have to flip it first in order for the replacement to make any sense.

“He’s the one whom I saw…”
Flip: I saw whom. I saw him. “Whom” is correct.

The use of whom is declining. You could probably get by just using it after prepositions. She is the one to whom I was engaged.

Who gave it to whom?

She gave it to her.

I always say “Who is he?”.
If you can say he, use who. If you can say him, use whom.

Ok. Would you post the grammar website/ or websites that you recommend?

So, whether it’s “According to who is it that 2+2 is ...” or “Who said “2+2 is…” , the person is Bob or it’s he since he is the subject in either sentence. It’s not “Him said 2+2 is…” It’s “he said 2+2 is ..“_
The “according to” part doesn’t change him into the object. Correct or not correct.

@Demosthenes Sorry, you posted a link. Thanks!

You are making this difficult. In both sentences replace who/whom with he/him.

According to him is it that 2+2 is… – Use whom
He said that 2+2 is… – Use who

When the sentence requires ‘whom’ rephrase it.

The rule is: the relative pronoun takes its case from its clause.

*In “according to who you are”, who is the subject of the verb are.
Similarly, “depending on who you are.”
https://forum.wordreference.com/threads/according-to-who-m-depending-on-who-m.624270/ *_

I thought you were having trouble distinguishing subject from object. Once you have made that determination, it is pretty easy. Who is always a subject and whom is always an object. I would still caution against using whom in every case where it is an object. Would you ask, “Whom do you trust?” It follows the rule but it sounds pedantic.

@LostInParadise I just posted the OP asking for websites links that demonstrate it the difference. . But people ( including to me) felt like “according to whom” sounds right simply because the word “to” is there, as in “to whom it may concern”. But really as the website shows…

….I used to say “according to whom” until lately. I don’t know what helped me to correct myself but here:
https://www.fluther.com/213701/according-to-who-is-it-that-exercising-is-only-good-for/

It is really simple. But here’s a link to explain ti simply.
https://www.grammarbook.com/grammar/whoVwhom.asp

The “according to” part doesn’t change him into the object.

Yes it does. The word to is a preposition, and the noun or pronoun following it is the object of the preposition, thus should be “whom”.
Link

Yes, but in the sentence “It may not be important, depending on who said it”, you would use “who” even though “on” is a preposition because in this example “who” is the subject of its own clause and it’s the entire clause “who said it” that is the object of “on”.

GA, @Demosthenes! That is correct. Now if you can find a link to a page that illustrates the point…

…By the way I forgot to put quotation marks in my post my 3rd post in the thread: permalink
“The rule is: the relative pronoun takes its case from its clause.”

@Woodruff That’s the thing though, it’s not as simple as it looks on the surface.

@Strauss re. “Now id you can find a page that illustrates the point.” , see my 3rd post in the thread.