Preterite vs Imperfect

This is the lesson that ties everything together. Choosing between the preterite and the imperfect is one of the most challenging aspects of Spanish for English speakers, because English often uses the same form for both. In this lesson, we break down the distinction with clear rules, side-by-side comparisons, and plenty of examples.

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The Fundamental Distinction

Preterite	Imperfect
Completed action	Ongoing / habitual action
Has a clear beginning or end	Has no stated beginning or end
Happened a specific number of times	Happened an unspecified number of times
Moves the story forward	Provides background or context
What happened	What was happening

Analogy: Imagine watching a film. The imperfect is the scenery, lighting, and mood music. The preterite is the plot — the events that drive the story forward.

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Same Verb, Different Meaning

Some verbs change meaning depending on whether they are in the preterite or imperfect. This is because the preterite emphasises the beginning or completion of a state, while the imperfect describes the ongoing state:

Verb	Imperfect meaning	Preterite meaning
saber	knew (a fact)	found out / learned
conocer	knew (a person) / was familiar with	met (for the first time)
querer	wanted	tried to
no querer	did not want	refused
poder	was able to (general ability)	managed to / succeeded in
no poder	was not able to (general)	failed to / could not (specific attempt)
tener	had (possession, state)	got / received
tener que	had to (ongoing obligation)	had to (and did it)
costar	cost (at the time)	cost (at the moment of purchase)

Examples of Meaning Changes

Imperfect	Preterite
Sabía la verdad. — I knew the truth.	Supe la verdad. — I found out the truth.
Conocía a Juan. — I knew Juan.	Conocí a Juan. — I met Juan (for the first time).
Quería ir. — I wanted to go.	Quise ir. — I tried to go.
No quería comer. — I didn't want to eat.	No quise comer. — I refused to eat.
Podía nadar. — I could swim (ability).	Pude nadar. — I managed to swim (specific occasion).
No podía dormir. — I couldn't sleep (ongoing).	No pude dormir. — I failed to sleep (that night).

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Side-by-Side Comparisons

The Same Event Described Differently

Imperfect (background)	Preterite (event)
Llovía mucho. — It was raining a lot.	Llovió mucho. — It rained a lot.
(Describes the weather as background)	(States that rain occurred as a completed event)
Estaba enfermo. — He was sick (state).	Estuvo enfermo. — He was sick (and recovered).
(Ongoing condition, no end stated)	(Bounded period — he got sick and got better)
Vivía en Madrid. — I lived in Madrid (at that time).	Viví en Madrid. — I lived in Madrid (for a specific period, now over).
(Ongoing situation, no timeframe)	(Completed period, e.g., "for two years")

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Decision Framework: Which Tense?

Ask yourself these questions in order:

1. Is it a habitual or repeated action?

Yes → Imperfect

• Siempre comía a las dos. — I always ate at two.

2. Is it a description, state, or background information?

Yes → Imperfect

• Hacía calor y el sol brillaba. — It was hot and the sun was shining.

3. Is it a completed, one-time event?

Yes → Preterite

• Comí a las dos. — I ate at two (on that specific occasion).

4. Does it have a definite beginning, end, or duration?

Yes → Preterite

• Estudié durante tres horas. — I studied for three hours.

5. Is it an interrupting event in a longer background action?

Interrupting event → Preterite. Background → Imperfect

• Leía (imperfect) cuando sonó (preterite) el teléfono. — I was reading when the phone rang.

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Signal Words Cheat Sheet