In this problem, we need to conjugate each verb in parenthesis in the imperfect. The imperfect is used to talk about past actions, conditions, or events that occurred regularly or frequently or that were in progress in a moment in the past. There are two forms in this verbal tense, namely: Regular Imperfect Forms and Irregular Imperfect Forms.
You can recognize only two sets of endings for regular imperfect, one for ar verbs and one for both er and ir verbs. If you want to conjugate a regular verb in the imperfect, you must remove the infinitive ending (ar, er, or ir) and add the imperfect ending that matches the subject as indicated in the first Table below.
In the imperfect tense, there are only three verbs with irregular conjugations, namely: ir, ser, and ver. This is shown in the second Table below.
So:
1. Right answer:
organizaban
¿Desde la época de los aztecas se organizaban los llamados tianguis?
Los aztecas can be replaced by ellos, so organizaban is the conjugation of the ar verb organizar for the third person plural (ellos – since the noun of the question is given in feminine form) in the imperfect. See from the first Table below that the ending that matches this subject pronoun is aban.
2. Right answer:
actuaba
¿Gael García Bernal actuaba en telenovelas antes de convertirse en estrella de cine?
Gael García Bernal can be replaced by él, so actuaba is the conjugation of the ar verb actuar for the third person singular (él - since the noun of the question is a man) in the imperfect. See from the first Table below that the ending that matches this subject pronoun is aba.
3. Right answer:
expresaba
¿Frida Kahlo expresaba en sus retratos el dolor de su vida personal?
Frida Kahlo can be replaced by ella, so expresaba is the conjugation of the ar verb expresar for the third person singular (ella – since the noun of the question is a woman) in the imperfect. See from the first Table below that the ending that matches this subject pronoun is also aba.
4. Right answer:
existían
¿Cuando llegaron los españoles al nuevo mundo ya existían otras culturas muy desarrolladas?
Los españoles by ellos, so existían is the conjugation of the ir verb existir for the third person plural (ellos – since the noun of the question is given in masculine form) in the imperfect. See from the first Table below that the ending that matches this subject pronoun is ían
5. Right answer:
eran
¿Las civilizaciones azteca, inca y maya no eran las únicas de la época precolombinas?
Las civilizaciones azteca, inca y maya by ellas, so eran is the conjugation of the verb ser for the third person plural (ellas – since the noun of the question is given in feminine form) in the imperfect. See from the second Table below that the ending that matches this subject pronoun is in fact eran
6. Right answer:
consideraba
¿La religión olmeca consideraba al jaguar como dios de la agricultura, la tierra y la lluvia?
La religión olmeca by ella (or esta), so consideraba is the conjugation of the verb considerar for the third person singular (ella/esta – since the noun of the question is given in feminine form) in the imperfect. See from the first Table below that the ending that matches this subject pronoun is in fact aba