Preterite vs imperfect: the short version
Both tenses describe the past. The preterite treats an action as a finished event: it happened, and it’s done. The imperfect describes the past as it was unfolding: what used to happen, what was going on, or what things were like. A useful picture is a film: the imperfect sets the scene, and the preterite is the action that moves the plot forward.
Use the preterite for…
- Completed actions at a set time: Ayer comí paella.
- A sequence of events: Abrió la puerta y salió.
- Actions with a clear beginning and end: Llovió todo el día.
- Sudden events and interruptions: De repente, sonó el teléfono.
Use the imperfect for…
- Habits and repeated actions: De niño, comía mucho chocolate.
- Actions in progress: Mientras yo cocinaba…
- Description, weather and feelings: Hacía frío. Estaba cansada.
- Time and age: Eran las diez. Tenía veinte años.
Words that point to each tense
Time expressions are the fastest clue. Ayer, anoche, el año pasado, una vez, de repente, en 2015 and hace dos días usually signal the preterite. Siempre, todos los días, cada mañana, normalmente, de niño, cuando era pequeño and mientras usually signal the imperfect. They’re strong hints, not guarantees, so always ask what the sentence is doing: reporting an event, or painting the background?
The classic pattern: one action interrupts another
When one past action interrupts another, the ongoing action takes the imperfect and the interruption takes the preterite: Yo leía cuando tú llamaste (“I was reading when you called”). Many sentences in this drill use that pattern, because it’s where learners get mixed up most often.
Common forms to know
| Verb | Preterite (yo) | Imperfect (yo) |
|---|---|---|
| hablar | hablé | hablaba |
| comer | comí | comía |
| ir / ser | fui | iba / era |
| tener | tuve | tenía |
| hacer | hice | hacía |
| estar | estuve | estaba |
The imperfect has only three irregular verbs: ser (era), ir (iba) and ver (veía). The preterite has many more, so spend extra time on it in typing mode.