What is the difference between the preterite and the imperfect in Spanish?
By Mert Yerekapan · Updated
Both tenses talk about the past, but the preterite treats an event as finished and the imperfect treats it as ongoing, habitual or background. Ayer comí pizza (Yesterday I ate pizza) is a completed event. De niño comía pizza todos los viernes (As a kid I ate pizza every Friday) is a habit with no clear endpoint.
The movie analogy
The image I like best is a movie:
- The imperfect is the scenery and the setting: what was going on, what things were like, what people used to do.
- The preterite is the plot: the events that happen and move the story forward.
Llovía y hacía frío cuando llegué a casa (It was raining and it was cold when I got home). Rain and cold are the background, so they're imperfect. Arriving is the event, so it's preterite.
When to use the preterite
- A single completed action: Compré un coche (I bought a car)
- A sequence of events: Me levanté, desayuné y salí (I got up, had breakfast and left)
- A specific time frame, even a long one: Viví en Lima tres años (I spent three years in Lima)
- A change or start: Tuve miedo cuando oí el ruido (I got scared when I heard the noise)
When to use the imperfect
- Habits and repeated actions: Siempre jugábamos al fútbol (We always used to play soccer)
- Descriptions in the past: Era alto y tenía el pelo negro (He was tall and had black hair)
- Age, time and weather: Tenía diez años (I was ten). Eran las ocho (It was eight o'clock).
- An action in progress: Leía cuando sonó el teléfono (I was reading when the phone rang)
- Feelings and states with no end in view: Estaba cansada (She was tired)
Both in one sentence
The classic pattern is a background action interrupted by an event:
Cocinaba cuando llegó mi hermano. (I was cooking when my brother arrived.)
Cooking is ongoing (imperfect). The arrival is the interruption (preterite).
Same verb, different meaning
Some verbs change meaning in the preterite, because it implies a moment of change:
| Verb | Imperfect | Preterite |
|---|---|---|
| saber | Sabía la verdad (I knew the truth) | Supe la verdad (I found out the truth) |
| conocer | Conocía a Marta (I knew Marta) | Conocí a Marta (I met Marta) |
| querer | Quería ir (I wanted to go) | Quise ir (I tried to go) |
| poder | Podía salir (I was able to leave) | Pude salir (I managed to leave) |
For more on the first two, see saber vs conocer.
Common mistakes
- Using the preterite for background description: for "the town was pretty back then", say El pueblo era bonito, not El pueblo fue bonito.
- Using the imperfect for a finished event with a stated length: Vivía en Lima tres años sounds off. Say Viví en Lima tres años.
- Forgetting that signal words help: ayer, una vez, de repente usually mean preterite. Siempre, a menudo, mientras, cada día usually mean imperfect.
What to do about it
Don't try to decide using rules in real time. Hear it in stories, where the tenses naturally alternate, and ask "is this scenery or plot?" My honest view is that this is learned by absorbing hundreds of examples more than by drilling charts.
Langtok, the app I built, is made for that kind of exposure: short Spanish stories you swipe through, where you can tap any word to translate it when a verb form throws you.