Ka hoa? But they taught me E ke hoa - Hey friend. I tried to memorize ke-article with hoa, but here we have ka.
There's an answer:
Would it still translate exactly if the subject and object were reversed?
yes but with different emphasis; in English emphasis is usually added by tonal inflection when speaking. In Hawaiian, you can do this with sentence structure as well.
What would be the Hawaiian for "She is an opponent today? "
He hoa paio 'o ia i këia lā.
I think that would be ʻO ia he hoa paio i kēia lā.