O to U Stem Changes in Spanish Preterite (Past) Tense

Ready to delve deeper into the Spanish preterite? Let’s explore a unique stem change that affects just a handful of verbs: the O to U stem change.

When Do We Use the Preterite?

The preterite tense is your go-to for talking about completed actions in the past. More specifically, it’s used for:

  • Actions completed in the past: Comí paella ayer (I ate paella yesterday)
  • Actions that occurred at a specific time: La película empezó a las ocho (The movie started at eight)
  • Actions that happened a specific number of times: Llamé tres veces (I called three times)
  • Actions that were part of a chain of events: Primero estudié, luego salí con amigos (First I studied, then I went out with friends)

How Do O to U Stem Changes Work in the Preterite?

This stem change is exclusive to the preterite tense and only happens in the third person singular and plural forms (él/ella/usted and ellos/ellas/ustedes). Here’s the pattern:

  • The ‘o’ in the stem changes to ‘u’ only in the third person singular and plural.
  • All other forms keep the original ‘o’.
  • These verbs also have irregular preterite endings.

Let’s conjugate the verb ‘dormir’ (to sleep) to see this in action:

Subject PronounPreterite Form
yodormí
dormiste
él/ella/usteddurmió
nosotros/asdormimos
ellos/ellas/ustedesdurmieron

Which Verbs Have This Stem Change?

There are only three verbs that follow this pattern in the preterite:

  • dormir (to sleep)
  • dormirse (to go to sleep)
  • morir (to die)

Example Sentences to Practice

  1. Yo dormí ocho horas anoche. (I slept eight hours last night.)
  2. Tú dormiste toda la mañana. (You slept all morning.)
  3. Él durmió profundamente después del largo viaje. (He slept deeply after the long trip.)
  4. Nosotros dormimos en una tienda de campaña durante el festival. (We slept in a tent during the festival.)
  5. Ellos durmieron hasta tarde el domingo. (They slept late on Sunday.)
  6. El famoso escritor murió en 1980. (The famous writer died in 1980.)
  7. Muchos soldados murieron en la batalla. (Many soldiers died in the battle.)

Key Takeaways

  • This stem change is exclusive to the preterite and only applies to three verbs.
  • The change only happens in the third person singular and plural.
  • These verbs also have irregular preterite endings.
  • Don’t confuse this with the O to UE stem change in the present tense.
  • The verb ‘poder’ in the preterite often translates to “managed to” or “was/were able to”.
  • Practice recognizing when to use the preterite. The stem change only matters when you’re talking about completed past actions.

While the O to U stem change affects only a few verbs, they are commonly used. Mastering this change will boost your fluency and confidence when speaking about the past in Spanish. ¡Sigue practicando!

Synonyms:

  • English: O to U Verbs in Simple Past, Past Simple, Preterite Tense, Past Historic
  • Spanish: Verbos de Cambio Radical O a U en Pretérito Indefinido, Pretérito Perfecto Simple, Pretérito

Learn specific conjugations:

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