Hello, Rachel! Despite the fact that there are lots of specific rules on when to use each one of them, we could sum it up by saying that: - The "pretérito perfecto simple" is used to talk about actions in the past which are finished. For example: ayer fui al supermercado. - The "pretérito imperfecto" is used to describe actions which are part of a rutine in the past (cuando era pequeño, iba al parque todos los días), to tell a story (el gato jugaba con el perro), or, finally, to describe characters or objects of the story (la mujer tenía el pelo negro). I hope I have helped you! :) Xiana

Hello, Rachel! Despite the fact that there are lots of specific rules on when to use each one of them, we could sum it up by saying that: - The "pretérito perfecto simple" is used to talk about actions in the past which are finished. For example: ayer fui al supermercado. - The "pretérito imperfecto" is used to describe actions which are part of a rutine in the past (cuando era pequeño, iba al parque todos los días), to tell a story (el gato jugaba con el perro), or, finally, to describe characters or objects of the story (la mujer tenía el pelo negro). I hope I have helped you! :) Xiana