I just got writing the English of this wrong about 5 times in a row because it's so unatural. I definitely agree it's not a good sentence to use, and should either be removed or at least rewritten/more versions of the sentence accepted. We're trying to learn a language, not memorise exact lines from poetry and their translations.
Whose are these forests, I think I know. Whose forests are these, I think I know.
Although really there should be a question mark in those versions, I would never say "whose forests these are" in normal spoken language, except at the end of a sentence. I think that little switch of word order is what makes it particularly poetic, and probably what kept tripping me up, because it doesn't sound right as a standard English sentence (which made me assume the original sentence was the Ukrainian one).
If "Чиї це ліси, я думаю, я знаю" was a natural word order in Ukrainian, then it seems fair enough we should learn it's standard for there but we'd normally say it "I think I know whose forests these are", but if like you say the suggested translation sounds odd in both, then only accepting those exact translations means we're going to be spending a lot of time focusing on the word order of something that's going to make us sound odd in either language.
Sagitta, as a Moderator do you not have the discretion to remove or change this entire exercise. I agree with another comment that we are here to learn common language not poetry. There are far too many deviations from normal rules of language and speech used in poetry to be helpful.
Okay, I sent this phrase to my 22 year old niece in Ukraine (her mother, my 1st cousin, is a teacher, and my niece has her masters degree) and asked her to translate. Here was her response -
"I would translate “ Who owns these forests? I think, I know.” Seems like it’s a poem.
So there it is, another vote for poetry as its origin. So it seems this phrase was written with some "poetic license", as we say in the US.