Preterite vs Imperfect
The core distinction
Both are past tenses. The choice depends on how you frame the action, not when it happened.
| Preterite | Imperfect | |
|---|---|---|
| Frame | completed, bounded event | ongoing, unbounded state or habit |
| Think of it as | a snapshot (one moment, done) | a video (background, continuous) |
| Translates roughly as | I did, she went, he said | I used to do, she was going, he would say |
Same real-world event, different framing = different tense.
Decision guide
Ask these questions:
| Question | If yes → |
|---|---|
| Was it a one-time completed event? | Preterite |
| Did it happen a specific number of times? | Preterite |
| Was it a sequence of events (first… then…)? | Preterite |
| Did it interrupt an ongoing action? | Preterite |
| Was it a habit or repeated action? | Imperfect |
| Was it a background state or description? | Imperfect |
| Does it describe how things were (not what happened)? | Imperfect |
| Was it an ongoing action when something else occurred? | Imperfect |
Signal words
| Preterite | Imperfect |
|---|---|
| ayer (yesterday) | siempre (always) |
| anoche (last night) | nunca (never) |
| la semana pasada (last week) | a veces (sometimes) |
| hace [X] años ([X] years ago) | todos los días (every day) |
| una vez (once) | de niño/a (as a child) |
| de repente (suddenly) | antes (before / used to) |
| entonces (then) | generalmente (generally) |
| por fin (finally) | mientras (while) |
| ese día (that day) | cada semana (every week) |
| al final (in the end) | cuando era joven (when I was young) |
Side-by-side: same sentence, both tenses
| Preterite | Imperfect | Difference |
|---|---|---|
| Comí pizza. (I ate pizza — once, done) | Comía pizza todos los días. (I used to eat pizza every day) | single event vs habit |
| Fue al banco. (He went to the bank — that specific time) | Iba al banco los viernes. (He used to go to the bank on Fridays) | one event vs routine |
| Trabajé allí dos años. (I worked there for two years — period is over) | Trabajaba allí. (I worked/was working there — background state) | closed period vs ongoing state |
| Llamó a las 8. (She called at 8 — specific moment) | Llamaba siempre a las 8. (She always called at 8 — routine) | one-time vs habit |
| Vivieron en Madrid tres años. (They lived in Madrid for 3 years — over) | Vivían en Madrid. (They lived in Madrid — background description) | bounded period vs open state |
| Escribí la carta. (I wrote the letter — completed task) | Escribía cuando entraste. (I was writing when you came in) | completed action vs in progress |
| Empezó a llover. (It started raining — specific beginning) | Llovía toda la tarde. (It rained / was raining all afternoon) | start point vs continuous state |
| Llegaron ayer. (They arrived yesterday — single action) | Llegaban tarde siempre. (They always arrived late — habit) | single occurrence vs habit |
| Compré un coche. (I bought a car — completed purchase) | Buscaba un coche. (I was looking for a car — ongoing process) | completed result vs open process |
| Salimos temprano. (We left early — completed event) | Salíamos temprano de niños. (We used to leave early as kids) | single action vs past habit |
The classic combination: imperfect + preterite
A very common pattern: the imperfect sets the scene (background), and the preterite interrupts (specific event).
| Imperfect (background) | Preterite (interruption) | English |
|---|---|---|
| Dormía | cuando sonó el teléfono. | I was sleeping when the phone rang. |
| Caminaba por el parque | cuando empezó a llover. | I was walking in the park when it started to rain. |
| Estudiaba | cuando llegó mi amigo. | I was studying when my friend arrived. |
| Leía un libro | cuando se fue la luz. | I was reading a book when the power went out. |
| Comíamos | cuando entró ella. | We were eating when she came in. |
| Hablaba por teléfono | cuando lo vi. | I was talking on the phone when I saw him. |
| Era de noche | cuando llegaron. | It was night when they arrived. |
| Llovía | cuando salí de casa. | It was raining when I left the house. |
| Tenía 10 años | cuando aprendí a leer. | I was 10 years old when I learned to read. |
| Trabajaba en Madrid | cuando conocí a mi esposa. | I was working in Madrid when I met my wife. |
Same verb, different tense, different meaning
| Preterite | Imperfect | Meaning shift |
|---|---|---|
| (No) supe que llegaste. | (No) sabía que ibas a llegar. | I found out (moment of learning) vs I didn’t know (ongoing ignorance) |
| Quise llamarte. | Quería llamarte. | I tried to call you (and maybe did) vs I wanted to call you (unfulfilled) |
| Pude abrirlo. | Podía abrirlo. | I managed to open it (success) vs I was able to open it (ability existed) |
| Tuve que salir. | Tenía que salir. | I had to leave (and did) vs I was supposed to leave |
| Conocí a María. | Conocía a María. | I met María (first time) vs I knew María (ongoing relationship) |
| Costó cien euros. | Costaba cien euros. | I paid 100 euros for it vs it was priced at 100 euros |
| Sentí el terremoto. | Sentía dolor. | I felt the earthquake (instant event) vs I was feeling pain (state) |
| Pensé en decírselo. | Pensaba en decírselo. | A thought crossed my mind vs I was considering telling him |
| Tuve una idea. | Tenía una idea. | An idea struck me vs I was carrying an idea in mind |
| No quise ir. | No quería ir. | I refused to go vs I didn’t feel like going |
Common mistakes
- ❌ Using preterite for descriptions of past state → ✅ “Era muy joven” (imperfect), not “Fue muy joven”
- ❌ Using imperfect for a specific completed event → ✅ “Ayer comí” (preterite), not “Ayer comía”
- ❌ Translating “I was + -ing” always as imperfect → ✅ sometimes a preterite interrupts: “Dormía cuando sonó el teléfono”
- ❌ Treating signal words as absolute rules → ✅ they’re strong hints, not guarantees; meaning drives the choice
Summary
- Preterite = snapshot: completed, bounded, specific, sequential
- Imperfect = video: ongoing, habitual, descriptive, background
- Classic combo: imperfect (scene setting) + preterite (event that happened)
- Some verbs change meaning based on which tense is used (saber, conocer, poder, querer)
See also: Preterite — endings and examples.
See also: Imperfect — endings and examples.
See also: Present Perfect — the tense Castellano often prefers over preterite for today’s events.
See also: Past Tense Conjugation Table — all forms at a glance.