Preterite vs imperfect
A2 Contraste: indefinido e imperfecto 27 / 49
In short
Spanish has two simple past tenses and you must choose: the preterite (indefinido) reports a completed event — what happened; the imperfect paints the background — what was going on or used to be. Same past, different lens.
The rule
Both tenses are “past”. The difference is aspect — how you view the action, not when it happened.
Use the preterite (lesson 24) for:
- a single, completed action: Ayer comí paella.
- an action seen as a whole, with clear limits (even a long one): Viví diez años en México.
- a sequence of events that move the story forward: Entró, saludó y se sentó.
- a sudden change or reaction: De repente, sonó el teléfono.
Use the imperfect (lesson 26) for:
- the background / scene: Era de noche y llovía.
- habits and repeated actions: Todos los días paseaba.
- an action in progress: Ella leía tranquilamente.
- descriptions, plus age, time and weather: Tenía veinte años. Eran las dos.
- an intention that fell through — iba a + infinitive: Iba a llamarte, pero se me olvidó. The preterite that follows says what happened instead.
- what was still true at that moment, after a past verb of saying or knowing: Me dijo que el ascensor no funcionaba. A present fact (no funciona) steps back to the imperfect under dijo, supe, preguntó.
The interruption pattern. A very common combination: an ongoing action (imperfect) is cut short by a sudden event (preterite) — exactly like English “was …-ing … when …”:
Yo dormía cuando sonó el teléfono. — I was sleeping when the phone rang.
The ongoing half can also be estaba + gerundio, which makes the “in progress” reading explicit: Estaba durmiendo cuando sonó el teléfono. The simple imperfect (dormía) always works; estaba durmiendo rules out the habit reading.
Use mientras + imperfect for two simultaneous ongoing actions: Mientras cocinaba, escuchaba la radio.
Verbs that change meaning. A few verbs translate differently by aspect: the imperfect keeps the state, the preterite marks the moment it began or the completed act.
Forms & patterns
Meaning shifts (imperfect = ongoing state; preterite = completed act / onset):
| Verb | Imperfect | Preterite |
|---|---|---|
| saber | sabía = knew (a fact) | supe = found out, learned |
| conocer | conocía = knew (a person) | conocí = met (first time) |
| querer | quería = wanted | quiso = tried; no quiso = refused |
| poder | podía = was able to | pudo = managed to; no pudo = failed to |
| tener | tenía = had | tuve = got, received |
Aspect at a glance:
| Preterite (indefinido) | Imperfect (imperfecto) |
|---|---|
| what happened | what was happening / how it was |
| completed, bounded event | ongoing, open-ended background |
| sequence: y luego… | description; simultaneous: mientras… |
| sudden change | habit / repetition |
Examples
| Español | English |
|---|---|
| Mientras estudiaba, mi hermano puso música. | While I was studying, my brother put on music. |
| Ayer hacía sol, así que fuimos a la playa. | Yesterday it was sunny, so we went to the beach. |
| Conocí a María en 2019; ya conocía a su hermano. | I met María in 2019; I already knew her brother. |
| Leía el periódico cuando sonó el timbre. | I was reading the paper when the doorbell rang. |
| Estábamos cenando cuando llamaron a la puerta. | We were having dinner when someone knocked at the door. |
| De niña iba al parque, pero un día me caí. | As a girl I used to go to the park, but one day I fell. |
| Supe la verdad cuando hablé con ella. | I found out the truth when I spoke with her. |
| Eran las tres y todavía trabajábamos. | It was three o’clock and we were still working. |
Common mistakes
- Cuando era niño, fui a la playa cada verano -> … iba a la playa cada verano - a repeated habit is imperfect, not preterite.
- Ayer comía paella -> Ayer comí paella - a single completed meal is the preterite; the imperfect would make it a habit.
- La conocí bien (for “I knew her well”) -> La conocía bien - the ongoing state “knew” is imperfect; conocí means “met”.
- Estaba de noche -> Era de noche - background description of the setting is imperfect, and “it was night” uses ser, not estar.
- Dormí cuando sonó el teléfono (for “I was sleeping”) -> Dormía cuando sonó el teléfono - the interrupted ongoing action must be imperfect.
- La semana pasada era el examen -> La semana pasada fue el examen - an event that took place is the preterite, even though English says “was”.
Tips
- Ask “photo or video?” A finished snapshot -> preterite. A rolling background or description -> imperfect.
- Narration recipe: the imperfect sets the scene (weather, time, feelings, what was going on); the preterite moves the plot (what happened next).
- The interruption frame is reliable: [imperfect] + cuando + [preterite] = “was doing X when Y happened”.
- Memorize the meaning-shifters: sabía/supe, conocía/conocí, quería/quiso, podía/pudo — they come up constantly.
- Time markers help: ayer, de repente, un día, en 2020 -> preterite; siempre, mientras, todos los días, de niño -> imperfect.