Who Is Tom Bombadil?

When I heard that Stephen Colbert listens every evening to 15 minutes of a professor talking about Lord of the Rings, I went on line to look for the professor. He's Corey Olsen of Signum University. I have started catching up at the "Exploring The Lord Of The Rings With the Tolkien Professor" You Tube page. I skip the "field trips" because I'm not interested in them. I'm interested in the text. And today, in Episode 30, I finally got up to the question that I wanted to hear other people's answers to: What is Tom Bombadil?

And in the course of the discussion, it struck me that everybody, including Professor Olsen, is reading the first relevant passage wrong. Here is that passage:

'Fair Lady!' said Frodo again, after a while. 'Tell me, if my asking does not seem foolish, who is Tom Bombadil?'

'He is,' said Goldberry, staying her swift movements and smiling.

Everybody, including Professor Olsen, reads "He is" with the emphasis on the "is". BTW, that is the origin of the crazy delusion, debunked by Tolkien himself, that Tom Bombadil is Iluvatar. "He is" should be read with the emphasis on "He". Which is why Frodo is confused. Frodo already knows that that guy with the long beard who is taking care of the ponies is named "Tom Bombadil". As Professor Olsen points out, what Frodo meant, and what everybody who analyzes this stuff really means, is "what is Tom Bombadil", not "who is Tom Bombadil?"

Update on 6/8/19. In Episode 31, starting at about 30:30, Professor Olsen discusses the emphasis question.  He still puts the stress on "is" but his interpretation of Goldberry's answer is similar to my interpretation with the emphasis on "he".