When to use Imperfecto and Indefinido

Question

Hi,In many lessons and responses to questions, I have read that when deciding if you are to use imperfecto or indefinido, it is up to how the speaker thinks about the event. If the speaker thinks the event had a clear start and end, you should use indefinido, and if not you use imperfecto. Does this mean that it is entirely up to the speaker to decide which past tense is correct? I understand that there are situations where it is clear which is right and wrong, but I feel like in many cases it is a bit more ambiguous.

Accepted Answer

Hola Anton
Yes, it always depends on what the speaker wants to express, how they see the event in their mind. You may learn in the basic levels that you need to use the indefinido when you talk about "yesterday's" events: ayer fui, ayer vi, ayer comí ...(ayer iba?, ayer comía?...) - but later on when you work with more complex texts and learn about different nuances you will realise that you can also say something like this:
Ayer, en el campamento, teníamos mucho frío...
Yesterday, at the campsite, we were very cold...
The speaker here, despite referring to ayer, which is a time that is disconnected to hoy (when he's expressing this) puts the emphasis on the fact that they "were feeling cold" during the previous day, not on a precise moment or a limited time with an end, but during the day of yesterday. So, they choose the imperfect to convey this nuance. 
You may find this lesson useful. Have a look here.
Saludos
Inma