Spanish language Q&A Forum

What exercises could i do to practice this?

Nosotros estamos arriba. (We are arrived) . The answer is estamos instead somos. I thought estamos only use in place. Can you please give an example. 

on the test, the "correct" result was "tengo cincuentos años".  
Do numbers change according to the noun they are adjectives of?

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.

Are “que” and “quien” mostly interchangeable as relative pronouns when talking about a person? Or is there a subtlety that I’m missing? I always feel a little unsure when I use “quien” because it seems like Spanish speakers use “que” more often.

If I had answered, "Me estoy muriendo de sed" instead, would it be viewed as correct? 

Hi I am a bit confused between vuestro and tu for yours.  Could I say 'El chico es tu primo'?

Thanks

I found the speaker very hard to understand.