"Iu tago la radikoj de tiu arbo detruos la muron."
Why is this wrong? I feel it should be a valid answer, but I am not that sure to report it. Duolingo only accepts "Iutage" instead of "Iu tago".
Either "iutage" or "iun tagon" would be correct.
I did the same thing. Maybe "Iu tago" is wrong because it's just a noun that's not doing anything. I'll bet that "Je iu tago" (on some day) might be legitimate. I don't know for sure, though.
La Vortaro at LernuNet says: "iutage (iu·tag·e ← tag·o) = one day, someday"
I think you could be right with "Je iu tago". Any "spertulo" here?
Stultulo ĉi tie. Duo nun akceptas kaj 'je iu tago' kaj 'iun tagon'
The Esperanto here now is "Iam la radikoj de tiu arbo detruos la muron". I thought "iam" means sometime. Don't you need to say "iam tage" or something similar to mean some day?