English mostly gets by with one simple past tense and leaves the rest to context. Spanish makes you choose between two — preterite and imperfect — every time. Getting this right is less about memorizing endings — you already practice those on the conjugator — and more about deciding what kind of past you're describing.
Preterite is for a completed action — it started and it finished. Imperfect is for the backdrop — something that was ongoing, repeated, or just describing how things were.
One event, start to finish
Ongoing, repeated, or descriptive
Yo dormía cuando sonó el teléfono.
I was sleeping when the phone rang.
The imperfect draws the wavy background line — sleep was already in progress. The preterite is the single point that cuts across it: the moment the phone rang.
A handful of verbs are usually about mental or physical states rather than actions — so switching them to preterite doesn't just change duration, it changes what happened.
| Verb | Imperfect | Preterite |
|---|---|---|
| saber | sabíaknew (already had the info) | supefound out (the moment it landed) |
| conocer | conocíaknew, was acquainted with | conocímet for the first time |
| querer | queríawanted (an ongoing wish) | quisetried to (and it took real effort) |
| poder | podíawas able to (in general) | pudemanaged to (this one time) |
Take the quiz and see if you can tell preterite and imperfect apart in context.