Preterite vs imperfect
I'm listening to the Duolingo Podcast, episode 2: https://podcast.duolingo.com/episode-2-sin-miedo-55bd8628a9dc. I'm confused by the usage of preterite and imperfect in these two sentences: "En ese tiempo, para mí el amor fueron las noches cuando Martín me decía dormido “te quiero, corazón.” Eran las cosas simples, de todos los días, las cosas que hacíamos juntos." The second sentence continues the thoughts and context of the first sentence, but the tense changes. What's the reason behind this?
I like this question! It does feel like there's a bit of a strong logical link between the fixed "that time" and the on-going nights. Maybe if one is a fixed time, logically the other is the same time? Here's my go.
"At that time, for me love was" this is preterite because it frames a particular period of the past in which the other action happens less particularly. Maybe love was something else at other times, maybe not, but she (I'm just going to call the speaker a she for convenience?) states that at that time love was these nights. Love didn't used to be a pillow talk kind of night now and then, sino from the beginning to the end of that time, it was.
"the nights when Martin said to sleeping me, 'I love you, dear.'" this part changes to imperfect, because even though her definition of love is anchored to "that time," by using the imperfect she tells us the nights within that time were a tendency. Maybe she knows she defined love this way from a given Sunday until the second Wednesday, but if that's not important. She means we should know there used to be nights like this.
"They were the simple things, the everyday, the things that used to bring us together." This is imperfect for the same reason as the above. It's in the past, but it doesn't have a clear occasion. Within "that time," simple everyday things used to bring them together. It's not her idea to be particular specifying days or hours on which this is known to have occurred or wrapped up, just it was happening.
So the reason it changes from preterite to imperfect is because she is only briefly invoking a "that time," while most of her thought is about past trends occurring freely inside of "that time."