How about "din cand in cand"
What about”El uneori cumpără mere roșii”? Should that have been marked incorrect?
Repor it.. It seems your suggestion is good.
The Romanian translation Duolingo said is correct in the exercise is, "El cumpără câteodată mere rosii." Yet, at the top of this page it shows the correct Romanian translation is, "El cumpără uneori mere roșii." Which is correct?