Preterite vs Imperfect: A Clear Guide to Spanish Past Tenses.

English has one simple past tense. "I ate." "She called." "We walked." Spanish has two, and they're not interchangeable. The preterite (pretérito indefinido) and the imperfect (pretérito imperfecto) both refer to the past, but they describe it in fundamentally different ways. Getting them right is one of the biggest leaps in Spanish fluency.

The good news: the distinction comes down to a single underlying idea. Once you see it, everything else, the rules, the edge cases, the verbs that change meaning, falls into place.

The core idea

Think of a past event as a film. The preterite describes specific events: things that happened, started, or ended at a definite point in time. They're the plot: discrete moments that move the story forward.

The imperfect describes the background: the ongoing conditions, the habits, the scene that was already in progress when the plot events occurred. It's what was already happening, what used to happen, what things were like.

Sonó el teléfono mientras comía. The phone rang while I was eating.

Sonó (rang) is preterite, a specific event that happened and ended. Comía (was eating) is imperfect, the ongoing background action that was already in progress. Neither tense is wrong here. They're doing different jobs in the same sentence.

When to use the preterite

Use the preterite for:

Completed actions with a clear endpoint. Ayer trabajé ocho horas. Yesterday I worked eight hours. The working is done. It has a defined start and end.

Actions that happened a specific number of times. Llamé tres veces. I called three times. A counted, completed set of events.

A sequence of events. Entré, me senté y pedí un café. I walked in, sat down, and ordered a coffee. Each action completed before the next began.

Actions that interrupted something ongoing. Estaba leyendo cuando llegó. I was reading when he arrived. Llegó (arrived) is the interruption, a preterite event cutting into an imperfect background.

Reactions and changes of state. Cuando vi la nota, me alegré. When I saw the grade, I felt happy. A specific moment of emotional response.

When to use the imperfect

Use the imperfect for:

Ongoing or continuous past actions. Llovía cuando salí. It was raining when I left. The rain was already in progress.

Habitual or repeated past actions. De niño, comía cereal todas las mañanas. As a child, I used to eat cereal every morning. A pattern, not a single event.

Describing how things were: background and setting. El restaurante era pequeño y hacía calor. The restaurant was small and it was hot. Scene-setting, not plot.

Age, time, and mental/physical states in the past. Tenía veinte años. Estaba cansado. Quería dormir. I was twenty. I was tired. I wanted to sleep. States of being, not events.

Actions in progress at a specific past moment. ¿Qué hacías a las tres? What were you doing at three? The focus is on what was ongoing at that point.

How to conjugate the preterite

Regular preterite conjugations split into two patterns: one for -ar verbs and one shared pattern for -er and -ir verbs.

Regular -ar verbs (hablar)

Regular -er / -ir verbs (comer / vivir)

Note: the nosotros form of regular -ar and -ir verbs is identical in the preterite and present tense. Context usually makes the meaning clear: hablamos can mean "we speak" or "we spoke," and vivimos can mean "we live" or "we lived."

The preterite has a significant number of irregular verbs: ser/ir (fui), tener (tuve), estar (estuve), hacer (hice), poder (pude), poner (puse), saber (supe), venir (vine), decir (dije), traer (traje). These need to be learned individually, but many share similar irregular stems once you start to notice the patterns.

How to conjugate the imperfect

The imperfect is one of the most regular tenses in Spanish. There are only three irregular verbs in the entire tense. Most learners find this a relief after the preterite.

Regular -ar verbs (hablar)

Regular -er / -ir verbs (comer / vivir)

The three irregular imperfect verbs

Ser, ir, and ver are the only three irregular imperfect verbs. Everything else follows the -aba or -ía pattern above.

Time markers: words that signal each tense

Certain time expressions almost always signal which tense to use. These aren't absolute rules, but they're reliable shortcuts when you're unsure.

Preterite triggers: specific, completed time references:

• ayer: yesterday
• anoche: last night
• el lunes pasado / la semana pasada: last Monday / last week
• hace dos días / hace un año: two days ago / a year ago
• de repente: suddenly
• por fin: finally
• una vez, dos veces: once, twice

Imperfect triggers: habitual, ongoing, or descriptive time references:

• siempre, nunca, a veces: always, never, sometimes
• todos los días / todas las mañanas: every day / every morning
• de niño / de joven: as a child / when young
• cuando era pequeño: when I was little
• normalmente, generalmente: normally, generally
• mientras: while (the ongoing background action)

Both tenses in the same sentence

Preterite and imperfect frequently appear together. The imperfect sets the scene and the preterite delivers the event that disrupts it.

Dormía cuando sonó el despertador. I was sleeping (imperfect) when the alarm went off (preterite).

Hacía frío y llovía cuando llegamos al aeropuerto. It was cold and raining (imperfect × 2) when we arrived at the airport (preterite).

Vivía en Madrid cuando conocí a mi mejor amigo. I was living in Madrid (imperfect) when I met my best friend (preterite).

In each case: imperfect = ongoing backdrop, preterite = the event that happened against that backdrop.

Verbs that change meaning

A handful of common verbs have different English translations depending on which past tense you use. This trips up learners because the change in meaning can be significant.

These shifts in meaning aren't arbitrary. They follow the same preterite/imperfect logic. Sabía describes the state of knowing; supe describes the moment of finding out. Once you see it through the completed/ongoing lens, the meaning shifts feel natural rather than arbitrary.

A simple decision framework

When you're unsure which tense to use, ask yourself two questions:

1. Is this a specific, completed event, or an ongoing state/habit?
Completed event → preterite. Ongoing state or habit → imperfect.

2. Could you answer "how many times?" or "when exactly?"
If yes → preterite. If the question doesn't apply (it was just the backdrop) → imperfect.

Most cases resolve cleanly with these two questions. For the edge cases, like querer meaning "tried" vs "wanted," you'll develop intuition through exposure and practice.

Your next step: active practice

Reading about the distinction is the first step. The second is producing it under pressure, choosing the right tense without having time to think through the rules consciously. That only comes from practice.

Solo Una's daily verb practice covers both the preterite and imperfect, working through conjugations one tense at a time so the forms become automatic. Each daily session takes about two minutes and focuses on a single verb and tense, exactly the kind of focused repetition that builds the fluency to choose correctly without pausing to reason through it.

Download Solo Una on the App Store — free →

Summary

Preterite: completed, specific, countable events. Plot. Things that happened and ended.
Imperfect: ongoing, habitual, or descriptive past. Background. States, habits, and what was in progress.

The imperfect is almost entirely regular. Only ser, ir, and ver are irregular. The preterite has more irregulars to learn, but the regular patterns for -ar and -er/-ir verbs are consistent.

Watch for time trigger words: ayer, de repente, por fin point to the preterite; siempre, todos los días, mientras point to the imperfect. And when both tenses appear in the same sentence, the imperfect is almost always the backdrop and the preterite the event that breaks it.

For more on Spanish past tenses and conjugation, see the guide to the 25 most essential irregular verbs, many of which have important preterite irregulars covered in full.