Verified answer

okay, well, it depends on the context of the sentence, but one basic way to remember it is:

the preterite is used to talk about an action which has been completed, happened once and then ended.

for example, i went to the shops would be "fui a las tiendas" because you went to the shops once and it was not an ongoing event.

however, if you were to say "i used to go to the shops every day", then you would use the imperfect, because it is referring to an event which you would do frequently. therefore you would say "iba a las tiendas cada dia."

another example is if you said "i wanted to go to the shops." that would also use the imperfect, because you didnt simply want it for a minute and then stop; it was a desire which continued for some time, with no definite starting/ending point. therefore you would say "queria ir a las tiendas."

to conclude, you would use the preterite for a one off event, something which happened and then ended, such as eating a chocolate bar, listening to music, going to a concert etc. the imperfect, on the other hand, is either used for something which was done more than once on a regular basis, or for something which took place over an extended period of time.

hope this helps!

Preterite= done and over with actions

Imperfect: on going actions

yes, you're right. irregular preterite means verbs in the preterite tense that have stem changers when conjugated (ex: andar becomes anduv--)