There are actions that are spread over time, to snore or to play tennis for example. For me it is not always clear should I use Past Simple or Past Continuous for such actions. For me it is absolutely clear that I should use Past Continuous when the action is happening around some explicit or implicit point of time.
We were walking home when I met Dan
or
We were playing tennis at 10 a.m.
But this is not so clear when I don't have even implicit point of time. I've seen examples where Past Simple was used like
-What did you do yesterday morning? -I played tennis.
and I've also seen examples where Past Continuous was used like
You were snoring last night.
What would change in the meaning if I changed the sentences above to be like
-What were you doing yesterday morning? -I was playing tennis.
and
You snored last night.
I've also found example where both tenses were used for the same sentence. This table is from https://dictionary.cambridge.org/grammar/british-grammar/past-continuous-or-past-simple.
Doctors were treating patients in temporary beds and they were trying to do their best in a difficult situation. | Past continuous: writer chooses to show the events as ongoing at that time in the past. |
Doctors treated patients in temporary beds and they tried to do their best in a difficult situation. | Past simple: writer chooses to show the events as finished. |
To be honest, explanations in the right column are not completly clear for me and all my attempts to reduce all this to some well-defined system have failed. I can't decide what tense to choose in sentences like the ones I wrote above. I wonder how the thought process of native speakers is built when they choose tense in situations like this.