Spanish language Q&A Forum

This was the question in the test that led me to this lesson,  but the lesson doesn't address the issue of choosing the correct past tense.

Ustedes ________ separados el año pasado.You were separated last year.
The hint tells you to use the tense for estaban, but I don't understand why since this seems to be talking about a definitive time that something happened.  Either the action of separating happened last year or the circumstance of being separated happened last year. Can someone explain why we should choose estaban over estuvieron (ustedes) besides the fact that the "hint" tells us to?
Thanks in advance for  any help!

Let us imagine the following scenario. There is a crowd of people at a cinema. what would the ticket controller use to invite those who had bought tickets in advance. haya or han comprado/reservado?

I always equate 'impersonal' with 'passive', as they seem to express the same thing. And, I've always used 'se' to express passive. So using third person is new to me, and I'm confused by this lesson and a question Kwiziq asked me to translate: 

'They took ages to build the hospital'

 among the choices were:

Han tardado mucho en construir el hospital (correct)

Se han tardado mucho en construir el hospital (incorrect)

Can someone explain why the second one is wrong.

Here are two other similar examples I found on Kwiziq that relate to this:

Tardaron mucho en construír los apartamentos = It took a long time to build the apartments.

Se tardó mucho en construir este hospital = It took (them, whoever built it) a long time to build this hospital.

Why isn't it en EL verano?

I am unsure why you choose imperfect for being able to see the view on that particular occasion. 

What is the rule regarding seasons of the year. When do we use the definite article el and when not. En el invierno/en invierno.

Thank you

The first person plural of present tense "to work" is nosotros trabajamos. The simple past is also nosotros trabajamos. Is the difference in translation based on context?  I may be overthinking this, but say it's noon and my mom asks me "how are you guys doing?" "Como estan?" and I reply "nosotros trabajamos."  Am I saying "we work (later) today" or "we worked (this morning)"?  I guess I'm supposed to follow this up with "esta manana" or "despues" to avoid confusion?