'Nunca' and 'siempre' in the past: Preterite or imperfect?

Question

It is commonly taught that the imperfect is used to describe general facts and habitual or recurring actions in the past. But what about sentences with the adverbs 'siempre' and 'nunca' and the peculiar cases of verbs like 'saber' and 'poder'? Which of the following sentences is correct and why? Perhaps there are some native speakers here, who would also like to comment.

1. Nunca supe qué tenía mi abuelo. / Nunca sabía qué tenía mi abuelo.
2. Siempre supe quién era. / Siempre sabía quién era.
3. Ella nunca pudo resolver sus problemas. / Ella nunca podía resolver sus problemas.
4. Siempre jugó con su hermano./ Siempre jugaba con su hermano.

From what I have learnt, I would say that 'nunca' warrants the preterite since it states that an action never took place. On the other hand, one could also make the point that it is a statement of a general fact?

I would also say that 'siempre' denotes a general state or a habitual action, which then would require the use of the imperfect. It does not specify a specific point in time or demark the end of an action in the past.

So, I would say that the correct sentences would be the following.

1. Nunca supe qué tenía mi abuelo.
2. Siempre sabía quién era.
3. Ella nunca pudo resolver sus problemas.
4. Siempre jugaba con su hermano.

But what do you say? My choice here is based upon what I have learnt so far. But I am unsure of whether it is correct and whether the reasons I gave are correct.

Answer 1

This is a difficult question, but I would say that when "siempre" and "nunca" are combined with "saber" or "poder", the imperfect tense is used only if there are several different instances of information or challenges, and all (or none) of them were learned or achieved. The preterite is used if there is only one information or challenge (which, in the case of "nunca", means that the state of not knowing or not having achieved something persists today). For example:

• Jugábamos todas las semanas al póker, y yo nunca sabía qué cartas tenía mi abuelo (imperfect: they were different cards each time, and I never knew what they were).

• Nunca supe qué (enfermedad) tenía mi abuelo (preterite: my grandfather had only one disease, and I never knew what it was).

• Mis amigos me mandaban muchas cartas anónimas, pero yo siempre sabía quién era el que había escrito cada carta (imperfect: there were letters from different persons, but I always knew who wrote each)

• Siempre supe quién era el que me escribía cartas anónimas (preterite: only one person wrote anonymous letters to me, and I always knew who that person was).

• La estancia en la Antártica fue muy dura: cada día había un nuevo problema. Ella nunca podía resolver los suyos, y siempre tenía que pedir ayuda (imperfect: there are different problems every time).

• Ella nunca pudo resolver sus problemas de dinero (preterite: it was always the same kind of problem that she was never able to solve).

The fourth sentence does not use "saber" or "poder", and is, in my experience, always correct with the imperfect tense, as it is an habitual action in the past:

• Siempre jugaba con su hermano.

Answer 2

If fact, it is a quite interesting question because there's a lot of different ideas that can be expressed with siempre and nunca. The verb tense is not realy restricted.

Let's start with the word nunca

In

Nunca supe qué tenia mi abuelo

the meaning is clear.

The sentence

Nunca sabía qué tenía mi abuelo

is correct but incomplete because it warrants a parallel event.

For example, you can say

Cuando el profesor me preguntaba algo, nunca sabía la respuesta.

You can also use other tenses like:

Nunca he sabido qué tiene/tenía mi abuelo.
Nunca sabré qué tiene/tenía mi abuelo.
Caundo me preguntan, nunca sé que contestar.

In all these examples you can substitute the word nunca with siempre

Siempre supe qué tenía mi abuelo.
Cuando me preguntaban, siempre sabía la respuesta.
Siempre he sabido qué tiene/tenía mi abuelo.
Siempre sabré que mi abuelo me quería/quiere mucho.
Cuando me preguntan, siempre sé que contestar.

Of course, you can use other verbs with similar contruction posibilities.

Answer 3

It is possible to use "Nunca" and "Siempre" with both tenses, preterite or imperfect even for the verbs "saber" and "poder". In some situations it is possible to use any of the tenses for exactly the same situation and in some situations only one of the tenses is correct.

In the situations in which it's possible to use any of the tenses the preterite is used to refer to a period of time as a whole whereas the imperfect is used to refer to each moment included in a period of time (a continuous action). It's the choice of the speaker to use the preterite or the imperfect depending on what he wants to emphasize.

Both options in each of your 4 sentences can be used to refer to the same situation:

1. a) Nunca supe que tenía mi abuelo en la bolsa cuando regresaba a casa. The speaker is referring to a whole period during which he never knew something.

   b) Nunca sabía lo que tenía mi abuelo en la bolsa cuando regresaba a casa. The speaker is referring to each particular day during a period of time. On Mondays he didn't know, nor on Tuesdays, nor on Wednesdays, etc.

2. a) Siempre supe quién era. Referring to the whole period. During the whole period the speaker knew who it was.

   b) Siempre sabía quién era. Referring to each day during a period. Each day the speaker knew who it was.

3. a) Ella nunca pudo resolver sus problemas. Referring to the whole period.

   b) Ella nunca podía resolver sus problemas. Referring to each day during a period.

4. a) Siempre jugó con su hermano. Referring to the whole period.

   b) Siempre jugaba con su hermano. Referring to each day during a period.

The user wimi cited one example of a situation where only one of the tenses is correct. If the grandfather died from an illness then the preterite should be used: "Nunca supe que tenía mi abuelo". So depending on the situation it could be more appropriate to use one of the tenses but both tenses could be used to refer to the same situation in several cases and it's the choice of the speaker to use one of them.