A First Contrast Between Preterite and Imperfect
Stories often pair an ongoing scene with the event that changed it. Choose imperfect for the background and preterite for the bounded action in clear two-part examples.
Learning objective
Contrast imperfect background information with a completed preterite event.
A tense contrast is a choice between two ways of presenting past information. The imperfect opens the background or an action already in progress; the preterite presents a completed event with a boundary. Pairing them lets a simple Spanish story show both the scene and what happened within it.
Start with a dependable two-part pattern: imperfect background plus preterite event. Llovía cuando llegó el autobús means It was raining when the bus arrived. Llovía keeps the weather in view, while llegó advances the story with one completed arrival.
The same verb can appear in either tense because meaning depends on viewpoint, not on a permanent verb category. Leía el libro presents reading in progress; leí el libro presents the book-reading as completed. A duration does not automatically decide the tense, although a finished time frame often supports the preterite.
Use cuando carefully. It can introduce the completed event, as in Cocinábamos cuando sonó el teléfono, but the word itself does not select a tense. Ask what each verb contributes: was it the surrounding situation, or was it the bounded action that changed or advanced the narrative?
For a first reliable story, limit yourself to one clear background and one or two completed events. Después can then order the results: Hacía frío cuando salimos de casa. Después tomamos un taxi. This avoids treating the imperfect as an unfinished action and keeps the preterite from becoming a tense for every past sentence.
Examples
Yo dormía cuando empezó la tormenta.
I was sleeping when the storm began.
Dormía is in progress; empezó marks the completed beginning.
La tienda estaba llena, pero encontramos una mesa.
The shop was crowded, but we found a table.
The condition creates context before the successful event.
Mientras Ana estudiaba, su amiga llamó.
While Ana was studying, her friend called.
Mientras highlights the ongoing background action.
Eran las once cuando terminó la película.
It was eleven when the film ended.
Background time and completed ending have different narrative jobs.
Common mistake
- Instead of
- Hacía frío y, de repente, el autobús llegaba.
- Try
- Hacía frío y, de repente, el autobús llegó.
Hacía establishes the background condition, while de repente introduces the one completed arrival that advances this intended story. Llegó therefore supplies the preterite event. Llegaba can be correct in another context, such as a repeated arrival, but it conflicts with the single sudden event framed here.
Practice
Try it yourself
Choose and conjugate the correct tense: Mientras nosotros ___ (cenar), alguien ___ (llamar) a la puerta. Then add a second completed action saying that Luis opened it.