May I speak with Jordan?

Someone calls and asks, "May I speak with Jordan?"

English teachers taught me that the common "This is him" is incorrect. "This is he" is the right answer because the pronoun is renaming the subject as in "This is he who is speaking". "This is he" sounds worse than "This is him", I think, because the subject-verb-object word order is the most basic conceptual pattern for native speakers.* The common advice from style guides to avoid beginning sentences with "I" is evidence of this. A better solution would be "You are speaking with him".**

But it doesn't make sense to speak of oneself in the third person. The first person version "I am speaking" doesn't really answer the question either and is comically self-evident. "Speaking" is a good but imperfect compromise. It answers the question succinctly which means a lot in communication even if it suffers from a lack of precision. But don't be surprised if I answer "I am the Jordan with whom you wish to speak. However, I am busy and you may not speak with me now".

This leads to a couple more things about English I can't figure out. We know that "I am speaking with him" is correct versus "I am speaking with he". Then I read this sentence "Agreeable people will go with whoever makes a suggestion" and I'm stumped. Who is the subject here? The prepositional phrase strongly suggests using whomever and implying that agreeable people is the subject. So why whoever? If we look at the alternate constructions "Agreeable people will go with he who makes a suggestion" and "Agreeable people will go with him who makes a suggestion" then the former seems correct. After all, we would say "he makes a suggestion" and not "him makes a suggestion". The phrase "whoever makes a suggestion" functions informally, if not formally, as an independent clause and therefore has a subject-verb-object construction its corresponding cases.

* It is also this near functioning, I think, which partially causes people to use the object case for comparatives. The argument for the subject case is perfectly logical i.e., "She is taller than him" versus "She is taller than he [is]", but if we look at the rule for prepositions which are a kind of comparison of the subject to an object: she is near him, she is by him, she is far from him, she is away from him, she is beside him, etc., it's a reasonable inference for comparatives.  I mean we can't even settle 0^0 in the mathematical realm so a little prudence among grammarians is a good idea.

** I know that the correct American use is to place periods within the quotation but this is one case where I think the British use is arguably better. A quote is an insert and the period should always notate the end of the writer's sentence even if it at the expense of the quote's. That's not to say a period cannot do both but that leads to this horrific construction. "This is he who is speaking.". Then again, there was a time when I thought the multitude of parentheses at the end of complex expressions was dumb and now I can't live without them.