I struggle to understand how to use correctly some tense.
Talking about a past situation, which of these is correct?
1a) I had left the lights on, in case he had woken up.
1b) I had left the lights on, in case he woke up.
Another example. Say I explain a situation, I start in the present, but then want to talk about something that happened yesterday, should I say:
2a) "He is sleeping with his lights on. Two days ago, he had woken up at midnight and had been scared to death."
or should I say:
2b) "He is sleeping with his lights on. Two days ago, he woke up at midnight and was scared to death."