In active verbs it's easier to differentiate imperfect from perfect past
Eu fiz (I did it / I have done it)
Eu fazia (I did it / I would do it / I was doing it / I used to do it)
Eu fiz - It's something you may repeat in the future.
Eu fazia - you don't want to repeat that in the future.
But in Stative verbs there's some different reasons
Eu tive um carro (I had a car) **when you say I have had a car it sounds like "Eu tenho tido um carro". It's something you have for whole and you don't know for how long.
Eu tinha um carro (I had a car) **"I would have a car" is just "eu teria um carro mas não tenho, ou não terei" ...but I don't have it and I won't have it. "I used to have it" sounds like a meal, you know. "I was having it" either.
"Eu tive um carro" it sounds like you didn't have something but for a while you had.
"Eu tinha um carro" sounds like you were born with that thing (I know it's too much) and you lost it
So, you can use both: we weren't students (nós não éramos estudantes / nós fomos estudantes)
I hope I didn't mess it up
What is the verb from which 'fomos' comes. I think I am looking for the infinitive form of the verb? I obviously need some basic grammar lessons because I haven't a clue what 'imperfect' and 'past perfect' tenses are. I also seem to remember the term "pluperfect" from school 55 years ago. But I don't know what that is! So having been barrelling along with DL in the present tense for the past 4 months, progress is coming to a grinding halt for lack of knowledge of basic grammar. Such a pity....
Correct use of tenses is always one of the hardest things to fully understand about a language. I've been learning English for 5 years now, including speaking to native speakers on a daily basis for the past one-and-a-half years and I'm pretty sure I still mess the past tenses up a lot.
Well, sometimes it can lead to misunderstandings. "Eu não comeria isto" and "Eu não comerei isto" for example don't mean the same thing at all but are easy to mix up, for me at least. Even worse though is preterite vs imperfect. I know the difference but that doesn't stop me from using the wrong one whereever I can >.<