Preterite vs imperfect: two ways to describe the past

With caminé hasta la estación you report a walk to the station as a completed event. With caminaba hacia la estación you present the walking as ongoing at a past time. Both are about the past, but you give a different view of the action.

The forms caminé and caminaba are usually called the preterite and imperfect in English-language Spanish courses. Spanish also has other ways to refer to the past. In English people express distinctions too, through forms such as “walked”, “was walking” and “had walked”.

A whole event or an ongoing situation

With the preterite you commonly present an event as a whole, with its limits included in the account. With the imperfect you present a past situation without focusing on those limits.

With vivió en Madrid cinco años the speaker presents a five-year period as a whole. With vivía en Madrid cuando nos conocimos the speaker describes where the person was living when we met. From the imperfect we cannot tell whether they still live there now.

The distinction is often called aspect: how an event is viewed in time. It is not simply a choice between something that really ended and something that never ended.

How the forms work together

Consider a short account:

Llovía cuando salí de casa. Las calles estaban vacías. Caminé hasta la estación y compré un billete.

It was raining when I left home. The streets were empty. I walked to the station and bought a ticket.

With llovía and estaban the speaker gives background conditions. With salí, caminé and compré the speaker reports events in the account. This is a useful pattern to notice in stories, though not every use of either tense fits it.

Repeated events can take either form

For repetition you do not automatically need the imperfect.

Spanish	What the sentence presents
De niña, visitaba a mi abuela los domingos.	A childhood habit
El mes pasado visité a mi abuela cuatro veces.	Four visits within a completed period
Durante aquel verano fui a nadar todos los días.	Repeated swimming within that summer, viewed as a whole

Likewise, a clock time is not a compulsory preterite signal. With a las ocho cenábamos you can describe what we were doing at eight. With a las ocho llegó Ana you report Ana’s arrival.

Meaning changes depend on context

Conocí a Ana en una fiesta normally means I met Ana at a party. With conocía a Ana I say I already knew her. With supe la noticia ayer I describe finding out yesterday; with ya sabía la noticia, already knowing.

These examples are useful, but do not turn them into mechanical replacements such as “tuve always means received” or “quise always means tried”. Read the complete sentence. A bounded period of wanting or knowing can also be described with a preterite form.

You can use the preterite for emotions too. Fui feliz allí is valid Spanish: with it you present happiness during that period as a whole. With estaba feliz cuando llamaste you describe the state at the time of the call.

Practise the account you want to give

Write a short description of yesterday. Say what the situation was and what happened. Then change the time frame to a childhood habit or a completed holiday. Notice which forms need to change and why.

For further reference, the Instituto Cervantes grammar inventory includes past-tense forms and uses. Examples and feedback are especially useful when both choices are grammatical but you tell the story differently with each.