How do I use "to be" and "who/whom" to modify "you"?

Question

I would like to say the following in a way that is grammatically correct: "You, who I think is terrible, are still nice."

While I suspect I could get around it with a rewrite like "You, whom I find to be terrible, are still nice," or just "You, whom I find terrible, are still nice," the questions posed by the original form still interest me.

Also, in general, how are those verbs in comma-separated modifiers conjugated when they're referring to "you"? Which is correct, if either:
* "You, who excel at spelling, are also a good dancer."
* "You, who excels at spelling, are also a good dancer."

Why does this feel so awkward?!

Answer 1

Who= subjective case
Whom = objective case
whose = possessive case
It's simple. If the question is "Who called?"; the Answer would be He called, where He occupies the subject position; and who is answered by teh word He, therefore it would be in the subjective case.

Whom did she call? The answer to this question would be "She called him. The word whom is answered by the word "him", which is in the object position of the sentence. Since the question word is answered by the objective case, hence the question word would be in the objective case.
(The above rule doesnt apply for verbb "to be" as the very "to be will take no object)

In the above sentence, " who" modifies the subject "you" hence it cannot be used in the objective case and you cannot say, " you, whom i think..."

Now the punctuation part:
When a relative clause is defining the subject in the main clause and not merely describing it, it should not be separated with commas. However, if the relative clause is only describing it and not identifying the subject of the main clause, it should be separated by commas.

What does defining relative clause mean?

The hat that is on the wall is mine.
Main clause= The hat is mine.
Subordinate clause= that is on the wall

if the subordinate clause is identifying the subject in the main clause it is defining.

My hat, which is green, is a good buy.

Main clause= My hat is a good buy
Subordinate clause= which is green

Here the subordinate clause is not identifying the subject in the main clause, but is just describing it, so it is a non-defining relative clause.

So here, it would be You, who excels at spellings, is also a good dancer because "excellence at spellings is only a descriptive factor and not an identifying factor for the person.
Long answer, lots of concepts? Follow ups are invited :D

Answer 2

I think it sounds so awkward because who and whom generally refer to a third-person noun or pronoun. I don't know whether this is an actual grammatical rule or not. But if you do a search for usage of who and whom, every example involves third-person pronouns. If you use who or whom in conjunction with "you" or "I" you run into problems with what form of the verb to use.

"Tom, who excels at spelling, is also a good dancer."

"Excels" can be used with both "Tom excels" and "who excels." But it's a lot more problematic with "you" or "I."

"You excel at spelling" sounds fine. "who excel at spelling" sounds wrong, possibly (I really don't know) because who and whom cannot be used with first and second person pronouns.

If you go with "You, who excels at spelling, are...", you've shifted person TWICE if you use "are" instead of "is"! But you kind of have to, because if you leave the subordinate clause out, you are left with "You is also a good dancer." And I think if you remove the subordinate clause, you should be left with a grammatically correct sentence. I could be wrong.

My advice: Don't combine first and second person pronouns with who or whom like that.

Instead, please consider the following:

"You, an excellent speller, are also a good dancer. I think that's legal.

Answer 3

You can justify either construction, but not the use of "whom". "You" is the subject of the sentence, and "who" refers to the subject, so must remain in its nominative form.

As far as the second question goes, it should be "excel" (and it is simple to determine this, you would never say "you excels").

Generally, however, people avoid these kinds of comma constructions in written English.