1. Preterito Imperfect The preterite is used when the action has been completed. It can’t be an action that is being done more than once. The end or beginning is stated. The endings are É asteóamosasteisaron íisteióimosisteisieron The imperfect is used when the action is being done more than one time. EX: I walk down the street every day. You would use the imperfect tense.