Why the different spelling of hryvnas?
because of я... it's usually transliterated as ya
Я is supposed to be transliterated as "ia." The Library of Congress system represents all soft sounds with an "i" (є = ie, й = i, ї = ii [or in some cases ï], ю = iu, я = ia).
It's been corrected here.
Why гривні and гривень ?
Why so many different plurals ?