On my russian test, the problem was "Этот город строили пять лет, а сейчас его уже построили" (Red being what he corrected).
I asked him what was wrong with the translation of "This city was built in five years, and now it is already built." He answered that I mistook the sentence for passive tense which Russians rarely use; they tend to use something called Indefinite Personal (or so it looks like he scribbled on my paper). This would change the translation to "They built the city in five years, and they already already built it." Anyways, could anyone further elaborate on indefinite personal or whatever tense that would help me understand?
-Спасибо