The preterite and imperfect are two ways to present the past. The preterite views an event as a bounded whole: ayer trabajé means “I worked yesterday.” The imperfect opens a view inside a past situation: trabajaba can mean “I was working” or “I used to work.” The difference is perspective, not simply whether an action was short, long, or actually finished in real life.
Decide how you are presenting the event
Compare Viví en Lima durante cinco años (I lived in Lima for five years) with Vivía en Lima cuando te conocí (I was living in Lima when I met you). The first frames the stay as a complete period. The second places us inside that situation when another event occurred.
Five years is a long time, yet the first sentence uses the preterite. Duration alone does not choose the tense. Nor does the imperfect claim that someone still lives there today. It simply leaves the endpoint outside the view of that clause. Ask what the sentence contributes to the story.
Use the preterite to report the events
The preterite is useful for answering “What happened?” Entré, pedí un café y me senté means “I went in, ordered a coffee, and sat down.” Each verb advances the sequence. El martes vimos una película presents Tuesday’s viewing as an event.
A repeated action can also be bounded: La llamé tres veces means “I called her three times.” The calls are counted and presented together as a finished set. Words such as ayer and el martes help establish a time frame, but they are clues, not automatic tense switches. You still choose the perspective that serves your meaning.
Use the imperfect to show background and habits
Eran las ocho. Hacía frío. Yo tenía hambre means “It was eight o’clock. It was cold. I was hungry.” These details establish the scene. An ongoing action works similarly: Esperaba el autobús, “I was waiting for the bus.” We are looking inside the waiting.
For routines, try De niña leía antes de dormir (as a girl, I used to read before sleeping). A useful English translation may be “used to,” “would,” or a simple past. English “would” has other meanings too, so identify the habit rather than translating that one word mechanically.
Let both tenses work in the same scene
While I was making dinner, the phone rang.
Preparaba places dinner preparation in progress; sonó introduces the ringing event. The phone does not have to end the cooking permanently. The sentence only places a bounded event against an ongoing scene.
Try a longer story: El café estaba lleno. Busqué una mesa y encontré una junto a la ventana. Mientras esperaba, leía los mensajes de mi hermana. “The café was full. I looked for a table and found one by the window. While I waited, I was reading my sister’s messages.” Notice each verb’s narrative job.
Avoid time-word rules and translation traps
Siempre does not force the imperfect. Siempre estudiaba por la noche describes a past routine; Siempre me ayudó durante aquel año summarizes someone’s help across a bounded year. Both choices make sense. “Finished versus unfinished” becomes misleading if you treat it as a claim about today rather than the viewpoint in the past.
Some common verbs highlight the contrast: Sabía la respuesta describes having the answer, while Supe la respuesta al final often means finding it out. Conocía a Marta describes acquaintance; Conocí a Marta en junio commonly reports meeting her. These readings follow the scene rather than a separate tense dictionary.
Practice with a small story
Choose a form for the intended reading. 1. Ayer ___ una carta y la envié. (escribí / escribía: a completed sequence). 2. Cuando era pequeño, ___ aquí cada verano. (vine / venía: a routine). 3. ___ las diez cuando llegó Eva. (Fueron / Eran: scene-setting). 4. Mientras ___, llegó un mensaje. (estudié / estudiaba: studying in progress).
Show answers
1. escribí: the writing advances the sequence. 2. venía: a childhood routine. 3. Eran: background time. 4. estudiaba: an action in progress when the message arrived.
Write three sentences about yesterday: a background detail, an event, and another event. Read them as a connected story. This gives each tense a purpose beyond completing a conjugation chart.
Sources & further reading
Our examples and explanations are written for LSFR learners. These references provide further detail.