Preterite vs imperfect: two Spanish pasts
English gets by with one simple past (“I ate”); Spanish has two: the pretérito indefinido and the pretérito imperfecto. They are not random alternatives: one frames an action as a finished event, the other as an ongoing backdrop. Choosing between them is about how you see the action, not just when it happened.
Preterite = a completed event
The preterite (indefinido) reports something that happened and finished at a definable point: ayer comí paella (yesterday I ate paella), llegaron a las ocho (they arrived at eight). Think of it as a photograph: a single, bounded moment. Time markers like ayer, anoche, el lunes, de repente usually pull the preterite.
Imperfect = background and habit
The imperfect describes what used to happen, what was ongoing, or the scene around an event: de niño jugaba al fútbol (as a child I used to play football), llovía y hacía frío (it was raining and cold). Think of it as a film running in the background. Markers like siempre, todos los días, mientras, generalmente point here.
They work together in a story
Real narration uses both: the imperfect paints the setting, the preterite drops the events into it. Caminaba por la calle (imperfect, ongoing) cuando vi a Marta (preterite, the event that interrupts). This “setting + interruption” pattern is the single most common place both tenses meet, and mastering it unlocks most storytelling.
Verbs that shift meaning
A few verbs translate differently by tense. Sabía = I knew; supe = I found out. Conocía = I knew (a person); conocí = I met. Quería = I wanted; quise = I tried (and no quise = I refused). These are not exceptions. They follow the same logic: ongoing state (imperfect) vs a completed change (preterite).
Drill the pair, not each alone
Conjugating either tense is not the hard part; choosing between them is. That skill only grows from repeated exposure to both in contrast. In Verboteca the preterite and imperfect forms of each verb are separate cards scheduled by how well you know them, so the contrast that trips learners up gets the most practice.