Preterite vs Imperfect: When to Use Each Tense

The preterite and imperfect are the two main past tenses in Spanish — and knowing which one to use is the single biggest grammar challenge for intermediate learners.

The short version: preterite for completed actions, imperfect for ongoing or habitual ones. But the real distinction is more nuanced than that.

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The Preterite (Pretérito Indefinido)

Use the preterite for actions that are complete and bounded — they have a clear start, end, or both. The action is done, and you’re reporting it as a finished fact.

Single completed events

• Ayer comí paella. — Yesterday I ate paella.
• Llegué a las ocho. — I arrived at eight.
• Ella llamó tres veces. — She called three times.
• Cerré la puerta. — I closed the door.

Series of sequential events

The preterite is also used for a chain of actions where each one completed before the next began:

• Me levanté, desayuné y salí de casa. — I got up, had breakfast, and left the house.
• Entró, saludó y se fue. — He came in, greeted everyone, and left.

Events with specific time markers

Certain time expressions signal the preterite: ayer (yesterday), anoche (last night), la semana pasada (last week), hace dos años (two years ago), de repente (suddenly):

• La semana pasada viajé a Barcelona. — Last week I traveled to Barcelona.
• Hace tres años empecé a estudiar español. — Three years ago I started studying Spanish.
• De repente, empezó a llover. — Suddenly, it started to rain.

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The Imperfect (Pretérito Imperfecto)

Use the imperfect for actions that were ongoing, habitual, or without a defined endpoint in the past. You’re painting a background scene or describing what used to be true.

Habitual or repeated actions in the past

• De niño, comía cereal todos los días. — As a child, I used to eat cereal every day.
• Mis padres siempre trabajaban duro. — My parents always worked hard.
• Íbamos a la playa cada verano. — We would go to the beach every summer.

Background descriptions and setting the scene

• La casa era grande y tenía un jardín hermoso. — The house was big and had a beautiful garden.
• Hacía frío aquella noche. — It was cold that night.
• Las calles estaban vacías. — The streets were empty.

Ongoing actions that provide context

When one action was already in progress when something else happened, the background action uses the imperfect:

• Dormía cuando sonó el teléfono. — I was sleeping when the phone rang.
• Leía un libro cuando llegó. — I was reading a book when he arrived.

States of mind, emotions, and age

• Cuando era joven, quería ser actor. — When I was young, I wanted to be an actor.
• Tenía veinte años cuando llegué a Madrid. — I was twenty when I arrived in Madrid.
• No sabíamos la respuesta. — We didn’t know the answer.

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Using Both Together

The preterite and imperfect often appear in the same sentence — one sets the scene (imperfect), the other describes what happened (preterite):

• Llovía cuando llegué a casa. — It was raining when I arrived home.
• Estudiaba cuando mi amigo llamó. — I was studying when my friend called.
• Éramos jóvenes cuando conocimos a María. — We were young when we met María.

Think of the imperfect as the movie’s background shot, and the preterite as the action that interrupts it.

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Where the Rules Break Down

Saber and conocer change meaning depending on tense:

Verb	Imperfect	Preterite
saber	knew (as a state)	found out (the moment of learning)
conocer	knew (someone)	met (for the first time)

• Sabía que estabas aquí. — I knew you were here.
• Supe la verdad ayer. — I found out the truth yesterday.
• Conocía a su hermano. — I knew his brother.
• Conocí a su hermano en la fiesta. — I met his brother at the party.

Querer and poder also shift:

• No quise ir. — I refused to go (made the decision not to).
• No quería ir. — I didn’t want to go (general feeling).
• Pude hacerlo. — I managed to do it (succeeded in the end).
• Podía hacerlo. — I was able to do it (had the ability).

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Quick Reference

Use Preterite for	Use Imperfect for
Completed single events	Habitual/repeated past actions
Sequential actions	Ongoing background actions
Specific time markers	Describing past scenes/states
Sudden interrupting events	Age, emotions, mental states
Beginning or ending of something	Something that was “in progress”

Time word clues:

Preterite signals	Imperfect signals
ayer, anoche	siempre, nunca
el lunes pasado	todos los días
hace X años	de niño/a
de repente	mientras, cuando (background)
una vez, dos veces	a veces, frecuentemente

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