Do you use preterite/imperfect if the start date is specified but NOT the end date?

Question

Context: In 2018, the Spanish court announced it's decision on the gang rape case of "la manada". The verdict was widely considered unfair. The #Cuéntalo hashtag was first used by a reporter on the day of the verdict which overtime became viral and made the case famous around the world. Since I know when the case began to make an international impact and when it began to spread an awareness of feminist issues, but not when the things ended, would I use the preterite or the imperfect? I feel like it should be the imperfect especially for difundir since it could still be going on now.

"Además, el caso tuvo un impacto internacional. La periodista Cristina Fallarás tuiteó sus experiencias con la violencia sexual y utilizó el hashtag #Cuéntalo (Beatley, 2019). Dentro de diez días, el hashtag había sido retuiteado tres millones de veces y se había utilizado en 70 países. Parece que el caso difundió una conciencia de los problemas de calidad de género en España además del mundo."

Answer 1

The preterite should be used here because you are referring to the impact caused by the lawsuit. In other words, the decision on the lawsuit caused the “impacto internacional” to happen there and then, right when the decision was made. Hence it can be considered as a complete action.

Another way to approach this is from the imperfect. If you were to replace “tuvo” with “tenía”, your sentence would say “the lawsuit used to have an international impact.” It will highlight the idea that the court’s decision created international backlash in a “routine” manner. This is apparently not the case, because the controversial issue only caught the attention of the international community after the #Cuéntalo hashtag was created.

The same can be said for “difundir”.