Time Machine

Preterite vs imperfect: how to choose the right Spanish past tense

Choose fui or iba on the fly — events, habits, scenes — out loud.

GRAMMAR PACK · 6 LESSONS · B1

The choice is about meaning, not conjugation tables. The preterite is for completed events with an endpoint: ayer fui al mercado, mi hermana llegó a las ocho. The imperfect is for habits, descriptions and ongoing states: siempre íbamos a la playa en verano, hacía mucho calor ese día. They combine in one signature frame — imperfect for what was happening, preterite for what interrupted it: mientras comía, sonó el teléfono. Time markers do half the work: ayer, anoche, la semana pasada cue preterite; siempre, todos los días, cuando era niño cue imperfect.

Below: the sentences that make each rule stick, the verbs that change meaning between the two tenses (sabía vs supe) — and a way to practice the choice where it actually gets made: mid-sentence, out loud, in a real conversation. No drills.

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The phrases that carry the conversation

Preterite for completed punctual past actions

Ayer fui al mercadoYesterday I went to the market
Anoche cenamos en casaLast night we had dinner at home
Mi hermana llegó a las ochoMy sister arrived at eight
El año pasado visité a mis abuelosLast year I visited my grandparents

Imperfect for past habits and repeated actions

De niño jugaba al fútbol todos los díasAs a child I played soccer every day
Siempre íbamos a la playa en veranoWe always went to the beach in summer
Mi abuela cocinaba los domingosMy grandmother used to cook on Sundays
Los sábados veíamos películas juntosOn Saturdays we used to watch movies together

Preterite interrupting imperfect (mientras/cuando)

Mientras comía, sonó el teléfonoWhile I was eating, the phone rang
Cuando salí, empezó a lloverWhen I went out, it started to rain
Estudiaba cuando llegaron mis amigosI was studying when my friends arrived
Caminábamos por el parque cuando vimos al perroWe were walking in the park when we saw the dog

Regional Spanish

What locals actually say

Textbooks teach one word. Locals use several — pick your region's and stay consistent.

Méx coloquial: 'Ayer me aventé al mercado' ('aventarse' = ir/hacer algo con entusiasmo).
Arg (voseo): 'Anoche cenaste temprano, ¿no?'
Col: 'Ayer me fui de rumba con los parceros' ('parceros' = amigos).
LatAm general: en LatAm el pretérito domina sobre el pretérito perfecto compuesto (Esp: 'he ido' / LatAm: 'fui').
Caribe (PR/RD/Cu): 'Ayel fui pa'l malcao' (relajación de /r/ y /s/ en habla rápida).
Méx: 'De morro le entraba al fútbol todos los días' ('morro' = niño/joven).
Arg (voseo): 'Cuando eras pibe, ¿jugabas a la pelota?' ('pibe' = niño).
Col: 'De pelado, mi abuela me hacía changua' (memoria de infancia).
LatAm general: 'siempre íbamos…' es la fórmula universal para nostalgia ('always used to').
Caribe: 'Cuando era chamaquito' (Ven) / 'cuando era chamaco' (Méx) — 'when I was a kid.'

Watch out

Mistakes that mark you as a textbook speaker

Using preterite for a past habit.habitual or repeated actions in the past use imperfect — 'siempre íbamos a la playa', not 'siempre fuimos'.
Using imperfect for a single completed event with a clear endpoint.'ayer cené a las ocho' (preterite), not 'ayer cenaba a las ocho'.
Getting 'saber' wrong.imperfect 'sabía' = I knew (ongoing); preterite 'supe' = I found out (moment of discovery).

The part no drill site can do

No flashcards. You learn it by using it

Carla

Your grammar teacher for this pack

You won't conjugate a single list in the Time Machine lessons — you tell your own past, out loud, and Carla coaches the choices as you make them. She asks about your weekend, and you frame it like a native: one imperfect line for the mood (era una noche tranquila), preterite for what actually happened (anoche cenamos en casa). She throws you a marker — siempre, anoche, todos los días — and you build the sentence on the spot, until picking the tense stops being a decision at all.

Blank mid-sentence and nothing bad happens — she waits. That's the practice, without unnecessary judgement.

Finish the 6 lessons and Time Machine is yours — earned, not given.

First 10 lessons free · 10-minute spoken lessons · your AI coaching team remembers you

Quick answers

Questions people ask

What's the difference between the preterite and the imperfect?

The preterite reports a completed event with a clear endpoint: terminé el libro el sábado. The imperfect paints what the past was like — habits (mi abuela cocinaba los domingos), descriptions (la casa tenía un jardín grande), and ongoing states (estaba cansado y quería dormir).

What are the trigger words for preterite vs imperfect?

Ayer, anoche, la semana pasada, el año pasado → preterite. Siempre, todos los días, de niño, cuando era joven → imperfect. Native speakers treat these pairings as automatic.

What's the difference between sabía and supe?

Sabía = I knew (ongoing); supe = I found out (the moment of discovery): supe la verdad anoche. Same shift with conocer: conocía a Juan desde la universidad (knew him) vs conocí a tu madre en la fiesta (met her).

How do you say 'while I was eating' in Spanish?

Mientras comía… — imperfect for the ongoing action, preterite for whatever cut in: mientras comía, sonó el teléfono. Saying mientras comí is the classic giveaway mistake.

Do Latin Americans say 'fui' or 'he ido' for the past?

For a finished event, Latin American Spanish strongly prefers the preterite — ayer fui al mercado — where Spain often uses the compound past (he ido). If you're learning for Latin America, the preterite is the workhorse tense.