In this exercise, we are asked to fill in the blank spaces of the next sentence with the verbs’ preterite or imperfect. Also, we must keep in mind that we have to join the background action with the imperfect and the interrupting action with the preterite:

Mi hermana menor ______ **(estar)** en la clase de ciencias cuando ______ **(sonar)** la alarma contra incendios.

In this case, we have to conjugate the first verb into the imperfect tense **(estaba)** because we are talking about the background action, and then we have to conjugate the second verb into the preterite tense **(sonó)** because we are talking about the interrupting action.

Mi hermana menor **estaba** en la clase de ciencias cuando **sonó** la alarma contra incendios.

In this exercise, we are asked to fill in the blank spaces of the next sentence with the verbs’ preterite or imperfect. Also, we must keep in mind that we have to join the background action with the imperfect and the interrupting action with the preterite:

Nosotros ______ **(hablar)** de las obligaciones de la sociedad cuando mi amigo ______ **(salir)**.

In this case, we have to conjugate the first verb into the imperfect tense **(hablábamos)** because we are talking about the background action, and then we have to conjugate the second verb into the preterite tense **(salió)** because we are talking about the interrupting action.

Nosotros **hablábamos** de las obligaciones de la sociedad cuando mi amigo **salió**.

In this exercise, we are asked to fill in the blank spaces of the next sentence with the verbs’ preterite or imperfect. Also, we must keep in mind that we have to join the background action with the imperfect and the interrupting action with the preterite:

Constantino ______ **(caerse)** cuando ______ **(correr)** en el centro de la comunidad.

In this case, we have to conjugate the first verb into the preterite tense **(cayó)** because we are talking about the interrupting action, and then we have to conjugate the second verb into the imperfect tense **(corría)** because we are talking about the background action.

Constantino **cayó** cuando **corría** en el centro de la comunidad.

In this exercise, we are asked to fill in the blank spaces of the next sentence with the verbs’ preterite or imperfect. Also, we must keep in mind that we have to join the background action with the imperfect and the interrupting action with the preterite:

Yo ______ **(jugar)** al fútbol con mis amigos cuando José ______ **(meter)** un gol.

In this case, we have to conjugate the first verb into the imperfect tense **(jugaba)** because we are talking about the background action, and then we have to conjugate the second verb into the preterite tense **(metió)** because we are talking about the interrupting action.

Yo **jugaba** al fútbol con mis amigos cuando José **metió** un gol.

In this exercise, we are asked to fill in the blank spaces of the next sentence with the verbs’ preterite or imperfect. Also, we must keep in mind that we have to join the background action with the imperfect and the interrupting action with the preterite:

¿Tú ______ **(ver)** el accidente cuando ______ **(caminar)** a la escuela?

In this case, we have to conjugate the first verb into the preterite tense **(viste)** because we are talking about the interrupting action, and then we have to conjugate the second verb into the imperfect tense **(caminabas)** because we are talking about the background action.

¿Tú **viste** el accidente cuando **caminabas** a la escuela?