"Yesterday I ate in a new restaurant."
Translation:Ayer comí en un restaurante nuevo.
Hi all. Native Spanish speaker here. My two cents about this sentence: this is a very tricky phrase.
Grammatically, both "restaurante nuevo" and "nuevo restaurante" are correct and acceptable as a possible translation. However, I'm inferring about the English sentence that the speaker ate in a fairly newly inaugurated restaurant that has opened just recently. That would be precisely translated as the former one ("restaurante nuevo"). The latter makes more sense when trying to indicate that the speaker ate in a non-usual, distinct-from-yesterday-and-days-before restaurant. But in English I guess someone would say "Yesterday I ate in a different restaurant". In Spanish, the most common way would be "Ayer comí en otro restaurante".
So there's a subtle difference. Albeit, in common speaking they're failry interchangeable, as the context has always the last word in terms of meaning. In fact, my first answer was rejected, even though I'm a native speaker! Then I started to give it some more thought, and came here to help anyone who might have very valid doubts.
BTW "uno nuevo restaurante" -as I read Duolingo suggests- is broken Spanish.
It looks like you have reversed matters. "Nuevo" before the noun has a more figurative meaning. Thus, "un nuevo restaurante" would be the restaurant not tried before, regardless that it was established in 1918! However, "un restaurante nuevo" would make us visualize a place just finished by the contractor last week.