Imperfect vs Preterito help?

Question

While I was doing my homework and corrected it, I stumbled upon a sentence that said: Un dia de primavera, Antonio y Alicia (viajar) por el campo.

We were supposed to put the correct form of either preterito or imperfecto and it turned out to be viajaban and NOT viajaron. Could anyone explain?

Answer 1

Think of the translation for imperfect as being "were traveling". It make sense to say:

One day in spring, Antonio and Alicia were traveling through the countryside.

To travel is not a specific event that happens and is completed in a single moment in time. It is more of a process. The equivalent of using the preterite tense, in English, would be:

One day in spring, Antonio and Alicia traveled through the countryside.

Note that you could, I suppose, technically use the preteirte tense, but would be far more likely to use the imperfect.