Preterite vs Imperfect in Spanish

Overview

One of the most important -- and most challenging -- aspects of Spanish grammar at the B1 level is understanding when to use the pretérito indefinido (preterite) versus the pretérito imperfecto (imperfect). Both tenses describe the past, but they frame past events in fundamentally different ways.

The preterite treats an action as a completed event -- something that started, happened, and ended at a definite point. The imperfect, by contrast, presents an action as ongoing, habitual, or descriptive -- it sets the scene, describes how things used to be, or shows what was happening when something else occurred.

Think of it this way: if the past were a movie, the imperfect would be the background scenery and ongoing action, while the preterite would be the key plot events that move the story forward. Mastering this distinction is what separates a basic Spanish speaker from a confident storyteller.

How It Works

When to Use the Preterite (Indefinido)

Situation	Example	Translation
Completed action at a specific time	Ayer comí paella.	Yesterday I ate paella.
Action with a clear beginning or end	La película empezó a las ocho.	The movie started at eight.
Chain of sequential events	Llegué, me senté y pedí un café.	I arrived, sat down, and ordered a coffee.
Action that happened a specific number of times	Fui tres veces.	I went three times.
Interrupting action	Llamó a las tres.	He called at three.

When to Use the Imperfect (Imperfecto)

Situation	Example	Translation
Habitual/repeated past action	Siempre comía a las dos.	I always used to eat at two.
Ongoing background action	Llovía mucho.	It was raining a lot.
Physical/emotional description	Estaba cansado.	I was tired.
Age, time, weather in the past	Tenía diez años.	I was ten years old.
Two simultaneous ongoing actions	Mientras cocinaba, escuchaba música.	While I cooked, I listened to music.

Using Both Together

This is where the magic happens. In narratives, the imperfect sets the scene and the preterite advances the action:

Pattern	Example	Translation
Background + event	Llovía cuando salí.	It was raining when I left.
Description + action	Estaba cansado, así que me fui.	I was tired, so I left.
Ongoing + interruption	Leía cuando llamó.	I was reading when he called.
Habit + change	Antes fumaba. Dejé de fumar.	I used to smoke. I quit.

Signal Words

Preterite	Imperfect
ayer (yesterday)	siempre (always)
anoche (last night)	todos los días (every day)
el lunes pasado (last Monday)	a menudo (often)
una vez (once)	generalmente (generally)
de repente (suddenly)	mientras (while)
en ese momento (at that moment)	de niño/a (as a child)
hace dos días (two days ago)	antes (before/used to)

Examples in Context

Spanish	English	Note
Llovía cuando salí.	It was raining when I left.	Imperfect (background) + preterite (event)
Antes fumaba. Dejé de fumar.	I used to smoke. I quit.	Imperfect (habit) + preterite (change)
Leía cuando llamó.	I was reading when he called.	Imperfect (ongoing) + preterite (interruption)
Estaba cansado, así que me fui.	I was tired, so I left.	Imperfect (state) + preterite (decision)
Cuando era niño, vivía en Madrid.	When I was a child, I lived in Madrid.	Both imperfect (habitual past)
Ayer conocí a una chica que era muy simpática.	Yesterday I met a girl who was very nice.	Preterite (event) + imperfect (description)
Quería llamarte pero no tenía tu número.	I wanted to call you but I didn't have your number.	Both imperfect (ongoing states)
El sol brillaba y los pájaros cantaban. De repente, oí un ruido.	The sun was shining and the birds were singing. Suddenly, I heard a noise.	Imperfect (scene) + preterite (event)
Todos los veranos íbamos a la playa. Un verano fuimos a la montaña.	Every summer we went to the beach. One summer we went to the mountains.	Imperfect (habit) + preterite (specific occasion)
Eran las tres cuando llegó.	It was three o'clock when he arrived.	Imperfect (time) + preterite (event)

Common Mistakes

Using preterite for descriptions and states

• Wrong: Fue las tres de la tarde. Hizo calor.
• Right: Eran las tres de la tarde. Hacía calor.
• Why: Time, weather, and descriptive states in the past use the imperfect because they are ongoing background conditions, not completed events.

Using imperfect for completed, one-time events

• Wrong: Ayer comía paella en un restaurante.
• Right: Ayer comí paella en un restaurante.
• Why: A specific, completed event at a known time (yesterday) calls for the preterite. The imperfect would imply you were in the middle of eating (and something interrupted you).

Confusing "knew" with conocer/saber

• Wrong: Conocía a María ayer. (when meaning "I met her")
• Right: Conocí a María ayer.
• Why: Conocer in the preterite means "met (for the first time)," while in the imperfect it means "knew/was acquainted with." Several verbs shift meaning between these tenses.

Defaulting to one tense for entire narratives

• Wrong: Telling a story entirely in the preterite or entirely in the imperfect.
• Right: Mixing both: Era un día bonito (imperfect). Decidí salir (preterite). Caminaba por el parque (imperfect) cuando vi a un amigo (preterite).
• Why: Natural Spanish storytelling weaves both tenses together. The imperfect paints the picture; the preterite tells what happened.

Verbs that change meaning

Some verbs have different translations depending on the tense:

Verb	Preterite	Imperfect
saber	found out	knew
conocer	met (first time)	knew (was acquainted)
querer	tried to	wanted
no querer	refused	didn't want to
poder	managed to	was able to (general)
tener	got/received	had

Usage Notes

The preterite-imperfect distinction is consistent across all Spanish-speaking regions, though frequency preferences vary. In Spain, the present perfect (he comido) often fills roles that Latin American speakers give to the preterite (comí), but the imperfect functions identically everywhere.

In spoken Spanish, native speakers make this choice instinctively and almost never get it wrong. For learners, the good news is that context usually makes your meaning clear even if you pick the wrong tense. But working toward accuracy will make your Spanish sound significantly more natural.

This distinction has no direct equivalent in English, where "I ate" and "I was eating" only partially map onto the Spanish system. The imperfect covers more ground than the English past progressive.

Practice Tips

• Tell short stories about your past, consciously choosing between tenses: describe the setting (imperfect), then narrate what happened (preterite). Era un día bonito. Salí de casa. Caminaba por la calle cuando...
• Practice with the "movie" metaphor: pause and ask yourself "Is this the background or a plot event?" Background gets imperfect; plot events get preterite.
• Pay special attention to the meaning-changing verbs (saber, conocer, querer, poder). Write pairs of sentences showing each tense to internalize the difference.

Related Concepts

• Prerequisite: Imperfect Tense