Preterite vs Imperfect: Mastering Spanish Past Tenses

For most English-speaking learners, the Spanish past tense system is the single biggest grammar challenge at intermediate level. English has only one simple past tense — "I ate," "I was," "I went." Spanish has two — the preterite (pretérito indefinido) and the imperfect (pretérito imperfecto) — and choosing the wrong one doesn't just sound odd, it changes the meaning of what you're saying.

The good news: once you understand the underlying logic — not just the rules — the distinction becomes intuitive. This guide explains both tenses completely, then gives you the frameworks that make the choice automatic.

The Preterite (Pretérito Indefinido): Completed Actions

The preterite describes actions that are complete — they had a clear beginning, an end, or both. When you use the preterite, you are treating an event as a finished, closed unit of time.

Regular Preterite Conjugations

Note: -ER and -IR verbs share the same preterite endings.

Key Irregular Preterite Verbs

When to Use the Preterite: Four Key Signals

1. A specific completed action at a specific time:

• Ayer fui al supermercado. — Yesterday I went to the supermarket.
• El año pasado viajé a España. — Last year I travelled to Spain.
• Llegué a Madrid el martes a las tres. — I arrived in Madrid on Tuesday at three.

2. A sequence of completed events (the story spine):

• Me levanté, desayuné y salí de casa. — I got up, had breakfast and left the house.
• Primero visitamos el Prado, luego comimos en La Latina y después volvimos al hotel.

3. An action that lasted a specific, defined amount of time:

• Estudié español durante tres años. — I studied Spanish for three years. (and then stopped)
• Vivió en Argentina desde 2010 hasta 2015. — She lived in Argentina from 2010 to 2015.

4. A change of state — something that began:

• De repente empezó a llover. — Suddenly it started to rain.
• Cuando llegué al aeropuerto, supe que el vuelo estaba cancelado. — When I arrived at the airport, I found out the flight was cancelled.

Preterite Trigger Words

These time expressions almost always signal the preterite:

• ayer — yesterday
• anteayer — the day before yesterday
• el año / mes / lunes pasado — last year / month / Monday
• hace dos días / semanas / años — two days / weeks / years ago
• en 1992 / en enero — in 1992 / in January (specific past time)
• de repente — suddenly
• entonces — then (next in sequence)
• por fin — finally
• una vez — once / one time

The Imperfect (Pretérito Imperfecto): Ongoing Past

The imperfect describes the background of a story — ongoing states, habitual actions and descriptions in the past. When you use the imperfect, you are not treating an event as finished and counted; you are describing how things were or what used to happen.

Imperfect Conjugations

Imperfect Irregular Verbs — Only Three!

The imperfect is famously regular — only three verbs are irregular:

When to Use the Imperfect: Four Key Uses

1. Habitual or repeated past actions (used to / would):

• Cuando era niño, vivía en Perth. — When I was a child, I used to live in Perth.
• Todos los veranos íbamos a la playa. — Every summer we would go to the beach.
• De pequeña, tocaba el piano. — As a child, she used to play the piano.

2. Background descriptions — how things were:

• Era una tarde tranquila. El sol brillaba y los pájaros cantaban. — It was a quiet afternoon. The sun was shining and the birds were singing.
• El restaurante era pequeño pero muy acogedor. — The restaurant was small but very welcoming.

3. An ongoing action that was interrupted by a preterite:

• Dormía cuando sonó el teléfono. — I was sleeping when the phone rang.
• Leía un libro cuando llegó mi amigo. — I was reading a book when my friend arrived.
• Mientras caminaba por el parque, encontré diez euros. — While I was walking through the park, I found ten euros.

4. Telling the time, age, and mental/emotional states in the past:

• Eran las once de la noche cuando llegamos. — It was eleven at night when we arrived.
• Mi abuela tenía ochenta años cuando murió. — My grandmother was eighty years old when she died.
• Estaba muy cansado después del viaje. — I was very tired after the trip.
• Quería ir pero no podía. — I wanted to go but couldn't.

Imperfect Trigger Words

• cuando era niño/joven — when I was a child/young
• de pequeño/a — as a child
• siempre — always
• normalmente / generalmente — normally / generally
• a veces / a menudo — sometimes / often
• todos los días / fines de semana — every day / weekend
• mientras — while
• en aquella época — in those days / at that time
• antes — before / formerly

The Classic Combination: Preterite + Imperfect Together

The most natural storytelling in Spanish combines both tenses. The imperfect provides the background scene; the preterite moves the story forward:

Era un día de verano. Hacía calor y el cielo estaba despejado. Caminaba por la playa cuando de repente vi a un amigo de la universidad. Nos saludamos, hablamos durante media hora y quedamos para cenar esa noche.

Translation: It was a summer's day. It was hot and the sky was clear. I was walking along the beach when suddenly I saw a friend from university. We greeted each other, talked for half an hour and arranged to have dinner that evening.

Notice: era, hacía, estaba, caminaba (imperfect = background/ongoing) vs vi, saludamos, hablamos, quedamos (preterite = completed narrative events).

The Tricky Cases: When Both Are Possible

Certain verbs change meaning between preterite and imperfect:

Quick Decision Guide

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

• Is it a completed action (something that happened and ended)? → Preterite
• Is it background (what was happening / how things were)? → Imperfect
• Is it something that happened repeatedly or habitually? → Imperfect
• Is there a specific time reference (yesterday, last year, three times)? → Usually Preterite
• Is an ongoing past action interrupted by a new event? → Imperfect for ongoing, Preterite for interrupting event