How To Conjugate in the Imperfect Tense

As one of Spanish's two simple past tenses, the imperfect indicative has a conjugation that is essential to learn. It is the verb form used most often to describe conditions as they existed in the past, to provide background to events, and to describe habitual actions.

Using Estudiar as an Example Conjugation

As with some other conjugation forms, the imperfect indicative forms are made by removing the infinitive ending of the verb (-ar, -er or -ir) and replacing it with an ending that indicates who is performing the action of the verb.

For example, the infinitive form of the verb that means "to study" is estudiar. Its infinitive ending is -ar, leaving the stem of estudi-. To say "I was studying," add -aba to the stem, forming estudiaba. To say "you were studying" (singular informal), add -abas to the stem, forming estudiabas. Other forms exist for other persons. (Note: In this lesson, the forms "was studying," "was learning" and so on are used to translate the imperfect indicative. Other translations also could be used, such as "used to study" or even "studied." The translation used depends on the context.)

The endings are quite different for verbs that end in -er and -ir, but the principle is the same. Remove the infinitive ending, then add the appropriate ending to the remaining stem.

List of Conjugations for the Imperfect Tense

The following chart shows the conjugations for each of the three infinitive types. The added endings for each verb are indicated in boldface. The pronouns, often not needed in sentences, are included here for clarity.

-Ar verbs using lavar (to clean) as an example:

• yo lavaba (I was cleaning)
• tú lavabas (you were cleaning)
• él/ella/usted lavaba (he was cleaning, she was cleaning, you were cleaning)
• nosotros/nosotras lavábamos (we were cleaning)
• vosotros/vosotras lavabais (you were cleaning)
• ellos/ellas/ustedes lavaban (they were cleaning, you were cleaning)

-Er verbs using aprender (to learn) as an example:

• yo aprendía (I was learning)
• tú aprendías (you were learning)
• él/ella/usted aprendía (he was learning, she was learning, you were learning)
• nosotros/nosotras aprendíamos (we were learning)
• vosotros/vosotras aprendíais (you were learning)
• ellos/ellas/ustedes aprendían (they were learning, you were learning)

-Ir verbs using escribir (to write) as an example:

• yo escribía (I was writing)
• tú escribías (you were writing)
• él/ella/usted escribía (he was writing, she was writing, you were writing)
• nosotros/nosotras escribíamos (we were writing)
• vosotros/vosotras escribíais (you were writing)
• ellos/ellas/ustedes escribían (they were writing, you were writing)

As you may notice, the -er and -ir verbs follow the same pattern in the imperfect indicative. Also, the first- and third-person singular forms (the "I" and "he/she/it/you" forms) are the same. Thus estudiaba could mean "I was studying," "he was studying," "she was studying" or "you were studying." If the context doesn't otherwise indicate, a pronoun or subject noun is used before the verb in such cases to indicate who is performing the action.

Irregular Verbs

Only three verbs (and the verbs derived from them, such as prever) are irregular in the imperfect tense:

Ir (to go):

• yo iba (I was going)
• tú ibas (you were going)
• él/ella/usted iba (he was going, she was going, you were going)
• nosotros/nosotras íbamos (we were going)
• vosotros/vosotras ibáis (you were going)
• ellos/ellas/ustedes iban (they were going, you were going)

Ser (to be):

• yo era (I was)
• tú eras (you were)
• él/ella/usted era (he was, she was, you were)
• nosotros/nosotras éramos (we were)
• vosotros/vosotras erais (you were)
• ellos/ellas/ustedes eran (they were, you were)

Ver (to see):

• yo veía (I was seeing)
• tú veías (you were seeing)
• él/ella/usted veía (he was seeing, she was seeing, you were seeing)
• nosotros/nosotras veíamos (we were seeing)
• vosotros/vosotras veíais (you were seeing)
• ellos/ellas/ustedes veían (they were seeing, you were seeing)

Sample Sentences:

• Llamó a la policía mientras yo compraba drogas. (She called the police while I was buying drugs.)
• Así vestíamos hace 100 años. (This is how we dressed 100 years ago.)
• Se saturaba el aire con olores. (The air was saturated with odors.)
• ¿Qué hacían los famosos antes de convertirse en estrellas? (What did the famous people do before they became stars?)
• Estaba claro que no queríais otra cosa. (It was clear you didn't want another thing.) 
• Creo que todos eran inocentes. (I believe all were innocent.)
• En Buenos Aires comprábamos los regalos de Navidad. (We bought Christmas gifts in Buenos Aires.)
• Los indígenas vivíamos en un estado de infrahumanidad. (We indigenous people lived a state of subhumanity.)