Preterite Tense Conjugations of Ser & Estar

The Preterite Tense of Ser

As you know, there are two different verbs that both mean ‘to be’ in Spanish: ser and estar. In this lesson, you’ll be learning how to conjugate both of these verbs in the preterite tense. You’ll also be briefly reviewing when to use ser and when to use estar.

Besides being irregular in the present tense, ser is also irregular in the preterite tense. However, you may already know how to conjugate it, because ser is conjugated exactly the same as ir in the preterite tense. Do you remember how to conjugate ir in the preterite?

Preterite Tense of Ir

If you remembered how to conjugate ir, you also know how to conjugate ser in the preterite.

Preterite Tense of Ser

Both these verbs use the stem ‘fu-.’ The endings are almost like regular ‘-er’/’-ir’ preterite endings, except that the first person singular ending (-i) has no accent, the third person singular ending is ‘-e’ instead of ‘-ió,’ and the third person plural ending is ‘-eron’ rather than ‘-ieron.’ Since the yo form of ‘-ar’ verbs is ‘-é’ in the preterite, both fui and fue look like they could be the yo form, so students sometimes mistakenly say yo fue. So, be sure to remember, fui is the yo form and fue is the él/ella/Ud. form.

Ir or Ser?

Since ir and ser are identical in the preterite tense, you have to rely on context to tell which verb is being used. Usually, it is pretty easy to tell the difference between the two verbs. For one thing, ir is usually followed by the preposition a (to), since you usually go ‘to’ somewhere. However, if ir is reflexive (irse), it means to go away and can be used without the preposition a.

Let’s take a look at some sentences that use the preterite tense of ir or ser. Based on the context, decide which verb is being used:

1. Yo fui a la universidad el lunes por la mañana.
2. La película fue muy chistosa.
3. Ayer fue mi cumpleaños.
4. Mis amigos y yo fuimos al cine.
5. Mis padres se fueron por la tarde.

The Preterite Tense of Estar

Estar is another verb that is irregular in both the present and the preterite tense. But since it doesn’t look like any other irregular verbs that you already know, you will have to memorize it.

Preterite Tense of Estar

Instead of dropping the ‘-ar’ off the infinitive, which would give you the stem ‘est-,’ you use the irregular stem ‘estuv-.’ The endings are also different from the regular preterite ‘-ar’ endings. The endings for tú, nosotros, vosotros, and ellos/ellas/Uds. are the same as the regular ‘-er’/’-ir’ preterite endings: ‘-iste,’ ‘-imos,’ ‘-isteis,’ ‘-ieron.’ The endings for yo and él/ella/Ud. are like the regular ‘-ar’ preterite endings, except that they don’t have accent marks: ‘-e’ instead of ‘-é,’ and ‘-o’ instead of ‘-ó.’

Ser or Estar?

Remember, although ser and estar both mean ‘to be,’ they are not interchangeable. As a general rule, ser is used to talk about things that are fairly permanent, such as who or what people or things are, what they’re like, and where they’re from. Estar is used to talk about things that are more temporary, like how someone’s feeling today (sick, happy, worried, etc.).