Pense vs. Pensaba
I thought you liked chocolate. Translation Yo pense que te gustaba el chocolate or Yo pensaba que te gustaba el chocolate?
4 Answers
Pensaba que te gustaba el chocolate.
We use the imperfect here because the thinking process happened for a while, we don't exactly know for how long, but we can assume that we've been thinking this for weeks/years/ all your life. But we can't be sure, therefore undefined past actions take the imperfect.
If the thought happened once, instantaneously, then the preterit is used. Take this example into consideration:
Al ver la foto, pensé inmediatamente en ti.
Upon seeing the picture, I immediately though of you.
Differences wth pensar in the preterit and imperfect solely depend on conversational and personal context. "Pensaba que te gustaba" signifies something different than "pensé que te gustaba", as the latter would tell us that the thought is completed. It can get quite complicated, but for all teaching purposes I'd stick with the imperfect here regardless.
I would say "yo pensaba"...
Very good explanations all, however, it´s difficult to explain using these verbs (pensar / gustar) together. Usually when both imperfecto and pretérito are used together, it´s to indicate one action starting and stopping within the time frame of another ongoing action, ie: "Ayer cuando caminaba por la calle, se cayó un arbol grandísimo".
If this thought has been going on for some time, along with the liking of chocolate, my guess would be,
Pensaba que te gustaba el chocolate.
However, if the thought was instantaneous, another option could be, and using another verb,
Creí que te gustaba el chocolate.
