What is the difference between the imperfect past tense and the preterite past tense.

The Imperfect:Describes habitual actions/repeated actions in the past Could describe an ongoing action Could describe a simultaneous action Look out for time expressions like siempre, durante, a veces. All of these usually suggest the imperfective will be necessary Is the equivalent of was doing, was going in EnglishUses ía, ías, ía/aba, abas,aba endingse.g Cuando era pequeña bebía zumo de naranja todo el tiempoThe preterite: Describes completed actions in the past(clear beginning and end points)Describes consecutive actions, single events, events which were repeated a specified number of times, look out for/triggers: una vez, ayer,e.g Ayer mi hermana compró una nueva televisión Note: the preterite is often used with the imperfective to suggest interruption e.g caminaba cuando me encontré con el hermano de mi mejor amiga- here the interrupted action is the imperfective and the interrupting is the perfective. uses é, aste,ó, amos, asteis, aron or í, iste,ió, imos, isteis, ieron