El Imperio Galáctico se derrumbaba. Era un imperio colosal que se extendía a través de millones de mundos, de un extremo a otro de la inmensa espiral doble que era la Vía Láctea. Su caída también sería colosal, y además prolongada, porque debía abarcar un enorme periodo de tiempo.

Extracto de Fundación e Imperio de Isaac Asimov

What is the highlighted verb tense: sería / debía?
Please explain in detail from the beginning.

  • 1
    It would be a good idea to edit in to this what you think and what researches you have done.
    – mdewey
    Feb 23 at 13:29
  • Is that usage of "debia" an exact copy? (the translated text doesn't seem to be right)
    – ipp
    Feb 23 at 15:20
  • That is a translation from English and not good for asking about Spanish grammar.
    – Lambie
    Feb 23 at 18:37
  • 1
    I’m voting to close this question because the book is translated and therefore not a good source for questions about Spanish.
    – Lambie
    Mar 6 at 17:13

They are two different tenses.

Sería is in the condicional tense. In this sentence, it refers to an action that would happen in the future with respect to a time of reference in the past. It is similar to the conditional tense with "would" in English:

  • It was a colossal Empire [...]. Its fall would also be colossal.

Debía is pretérito imperfecto. It describes an action that was ongoing in the past.

  • Its fall would also be colossal, and also prolonged, because it had to span a long period of time.

It seems a strange choice of tense to me, as I would have used the condicional also here: "debería abarcar un enorme periodo de tiempo", or even better "abarcaría un enorme periodo de tiempo". The reason is that this is either a future action from the past perspective, or a hypothetical action. The pretérito imperfecto makes more sense if the action (the fall) was already happening at the point of time we are talking about, or if it is a direct consequence of another statement:

  • Los enemigos del Imperio sabían que la victoria no llegaría pronto. La grandeza del Imperio significaba que su caída debía abarcar un enorme período de tiempo.

Not the answer you're looking for? Browse other questions tagged or ask your own question.