imperfect vs preterite with cuando/mientras

Question

If I use words such as "mientras" and "cuando" does it usually require an imperfect verb conjugation?

Answer 1

I will add one more scenario, after first saying, as always, that Julian´s answers are good. Oops, I meant great.

Anyway, back in that semester when we learned such stuff, there were two common scenarios for mientras presented.

The first was as in Julian´s example as above and was called interrupted action, where an imperfect verbs is used to set the background or context, and then a preterite verb describe an action that happened (or interrupted) while the imperfect verb was acting.

Mientras jugaba en el parque, vi la chica más hermosa en todo el mundo - as per Julian.

Mientras cenaba, llegaron unos amigos. While I was eating, a few friends arrived.

Ya estaba duchándome cuando sonó el despertador I was already showering when the alarm clock sounded (rang)

As Julian mentioned, this one is probably the most common scenario for mientras.

But, there is a second, less common example we called simultaneous past actions, and involved using the imperfect twice. It is used to describe a pair of actions in the past that were happening at the same time and were ongoing or habitual. I´ll attempt to cite a couple examples below, but I´m a bit rusty, so take them with a grain of salt.

De infancia, después de almorzar, yo montaba mi bici mientras mi hermana jugaba con muñecas.

As children, after lunch, I would ride my bicycle while my sister would play with dolls.

Cuando éramos estudiantes estudiaba yo dos materías diferentes mientras mi novia estudiaba una materia y trabajaba.

When we were students, I studied two different subjects while my girlfriend studied 1 subject and worked.

So, mientras can be imperfect-plus-preterite, or, imperfect-plus-imperfect, I believe.

Well done! - 005faa61, Dec 5, 2013

Answer 2

This is hard to know but I will say No. You will use imperfect or preterite depending on which time you wish to use, saying something that already happened or going into past to speak in the present of that past, it works for both cases.

Agreed that it is impossible to say without context, but if I had to guess, just anecdotally, I´d say cuando is about 50-50 and mientras leans a little imperfect. - rogspax, Dec 5, 2013

Answer 3

Speaking about past tense; Cuando can be used in either. It depends on context

Mientras is usually used in a clause with an imperfect verb while the complementing clause is in preterit to indicate one action taking place within the timeframe of another, ie: Mientras jugaba en el parque, vi la chica más hermosa en todo el mundo, desgraciadamente traía anillo de casada.

Answer 4

Cuando era joven solia jugar baloncesto con mis primos cada sabado mientras esparabamos por nuestros madres.