Preterite vs Imperfect

The two simple Spanish past tenses split English's single past tense between them. The decision isn't subjective - the rules are clear once you have them.

The decision rules

Preterite for:

Completed actions in a closed time frame (ayer, la semana pasada, en 2020)
Actions with a specified duration that has ended (trabajé dos horas, viví allí cinco años)
A single event, or a sequence of events forming a narrative
The interrupting event in a "while X was happening, Y happened" structure

Imperfect for:

Habitual or repeated actions (every day, every Sunday, used to)
Ongoing past actions ("was X-ing")
Background description (the scene, the weather, ages, time of day)
Mental and emotional states (knew, wanted, thought)
The interrupted action in a "while X was happening, Y happened" structure

Time markers as triggers

Triggers preterite	Triggers imperfect




2020
	/
	a

If you see one of these in the sentence, it tells you which tense to reach for. When neither appears, you decide by context.

Side-by-side examples

Spanish (preterite)	Spanish (imperfect)	Notes
paella.	paella .	One occasion vs habit
Madrid .	Madrid .	Bounded duration vs background
.	.	One event vs habit
Ana a .	yo llegué, Ana .	Bounded events vs the ongoing one
.	.	Closed past vs setting the scene
(a specific one I bought and sold).	(the one I owned at the time).	Bounded ownership vs ongoing state

Interrupted action: the most common composite

A characteristic Spanish past-tense structure: imperfect for the ongoing action, preterite for the event that interrupts it.

llegué, María . (When I arrived, Maria was sleeping.)
con , . (While I was talking with my mother, the phone rang.)
duchándome . (I was showering when the water cut off.)

The imperfect sets the stage, the preterite delivers the event. This is the bedrock structure of Spanish narration.

Verbs that change meaning

Five common verbs shift their core meaning between the two tenses. Worth memorising as a set.

Verb	Imperfect (state)	Preterite (bounded event)
	= knew (a person, a place)	= met (for the first time)
	= knew (a fact)	= found out, learnt
	= wanted	= tried, made the attempt
no	no = didn't want	no = refused, decided not to
	= could, was able	= managed to, succeeded
no	no = couldn't	no = failed to, didn't manage
	= had (state)	= got, received (event)

Examples:

a 2010. (I met my wife in 2010 - the event.)
a María . (I knew Maria before university - the ongoing state.)
. (I found out the truth yesterday - moment of finding out.)
. (I had known the truth for months - state.)
llamarte no . (I tried to call you but I failed to - both bounded events.)
llamarte no . (I wanted to call you but I wasn't able to - ongoing state.)

These distinctions don't translate cleanly into English. Spanish is doing semantic work in the choice of tense.

Worked examples

a México y México. (Last year I went to Mexico and visited Mexico City.) - bounded preterite chain
, y yo a . (When I was a child, my family and I used to go to the beach every summer.) - habitual imperfect
María llegué a . (Maria was cooking when I got home.) - imperfect + preterite
y . (The restaurant was full and it was very hot.) - background imperfect
a a y a once. (I started studying at eight and finished at eleven.) - bounded preterite

Common mistakes English speakers make

Defaulting to the preterite for everything because it feels closer to English simple past. The imperfect covers habitual and ongoing past, and missing it is the surest marker of an English-speaking learner. Conversely, using the imperfect for a bounded event because the duration is long: Madrid is preterite (bounded duration, ended), not imperfect. And missing the meaning-shifting verbs - a María and a María are genuinely different sentences and shouldn't be used interchangeably.

Ayer paella en la ciudad. (one specific occasion)
Todas las noches paella en casa de mi madre. (every night)
Cuando era niño, mi familia y yo a la ciudad cada año.
El año pasado a México y vi Ciudad de México.
Mientras yo hablaba con mi madre, el teléfono.
Cuando llegué a casa, María por teléfono.
La gente hablaba y buen tiempo. (setting the scene)
a mi mujer en 2010. (the bounded event of first meeting)

Fill in the blank

0/8

Write the verb in the tense given in brackets. Watch your accents: comí and comía, habló and hablaba are different words.

Ayer paella en la ciudad. (comer, preterite) (comer, preterite)
De niño paella todas las noches. (comer, imperfect) (comer, imperfect)
Ana por teléfono cuando yo llegué. (hablar, imperfect) (hablar, imperfect)
Mi amigo con nosotros una sola vez. (hablar, preterite) (hablar, preterite)
El año pasado en Madrid dos años. (vivir, preterite) (vivir, preterite)
en Madrid cuando era joven. (vivir, imperfect) (vivir, imperfect)
Anoche a la ciudad con mis amigos. (ir, preterite) (ir, preterite)
Cada tarde a la ciudad. (ir, imperfect) (ir, imperfect)

Translation drill

0/6

Translate into Spanish, choosing the preterite or the imperfect to match the meaning. Keep the accents correct.

Yesterday I ate paella.
I used to eat paella every night.
When I was a child, we used to go to the city every year.
Maria was working when I got home.
I met my wife in 2010.
The people were talking and the weather was good.

Frequently asked questions

What is the easiest way to choose between preterite and imperfect?

Ask whether the action is bounded. If it has a clear start and end in the past (yesterday, last week, in 2010, for two hours), use the preterite: ayer comí paella. If it's ongoing, habitual, or background description with no end specified (every day, while, when I was young), use the imperfect: comía paella todos los domingos. The same English sentence can map onto either depending on context - 'I ate paella' could be comí paella (one specific occasion) or comía paella (used to, repeatedly).

Why does conocí mean met but conocía means knew?

A small set of common verbs change meaning between preterite and imperfect. Conocer in the imperfect means 'to know (someone or somewhere)' as an ongoing state - conocía a María (I knew Maria). In the preterite it means 'to meet (someone) for the first time' - the bounded event of first acquaintance: conocí a María en 2010 (I met Maria in 2010). Same pattern for saber (sabía = knew vs supe = found out), querer (quería = wanted vs quise = tried, no quise = refused), poder (podía = could vs pude = managed to, no pude = failed to).