Durante mi segundo año en la universidad, (1) [conocí] (conocer) a Carlos en una clase. Pronto (2) [nos hicimos] (hacerse) buenos amigos. Carlos (3) [era] (ser) una persona muy generosa que (4) [organizaba] (organizar) una fiesta en su casa todos los sábados. Todos nuestros amigos (5) [iban] (ir). Siempre (6) [había] (haber) muchas bebidas y comida, y todos (7) [bailaban] (bailar) y (8) [hablaban] (hablar) hasta muy tarde.
Una noche algunos de los vecinos de Carlos (9) [llamaron] (llamar) a la policía para decir que nosotros (10) [hacíamos] (hacer) demasiado ruido. Entonces (11) [vino] (venir) un policía a la casa y le (12) [dijo] (decir) a Carlos que la fiesta (13) [era] (ser) demasiado ruidosa. Nosotros no (14) [queríamos] (querer) terminar la fiesta. ¿Qué (15) [pudimos] (poder) hacer? Todos (16) [nos despedimos] (despedirse) aunque (17) [eran] (ser) solamente las once de la noche. Aquella noche Carlos (18) [aprendió] (aprender) algo importante. Hay que invitar también a los vecinos.

1. Pret: "I met Carlos." "Conocer" in the preterite means "to meet."
2. Pret: They quickly became good friends. This does not have a sense of something such as "while we were becoming good friends."
3. Imp: Describes the characteristics of Carlos.
4. Imp: He regularly organized parties.
5. Imp: They regularly attended.
6. Imp: There regularly were these things at the party.
7. Imp: Reguarly occurring action
8. Imp: Reguarly occurring action
9. Pret: "Una noche" marks a shift in the story from what used to happen regularly to what happened on one specific occasion. The neighbors calling the police is a one-time event.
10. Imp: They were making too much noise. This is an ongoing situation at the time of the phone call to the police.
11. Pret: The police officer arrived once.
12. Pret: one-time occurrence
13. Imp: The party was ongoing at the time of the comment by the police officer.
14. Imp: They did not want to end the party.
15. Pret: This is a statement that sums up the situation. "What could we do?"
16. Pret: Said goodbye once
17. Imp: Saying the time in the past is automatically a background description.
18. Pret: Carlos learned something once, not over the course of time.