I have been studying on the progressive and simple aspects. I understand their format and their nature. However, I still don't understand how to decide when to use one or the other. For instance:
Jeb wrote the first draft of his essay
Jeb has written the first draft of his essay
The same applies to:
He looks tired, because he stayed up all last night
He looks tired, because he had stayed up all last night
How do you decide which one is better? I find it hard to decide which one is better. Both sound correct to me. Is it better to write:
"He 'looked' tired, because he 'had stayed' up all night.
He looked tired, because he stayed up all night.
What is the difference?