My colleague asked me why I was so tired this morning.
I answered as follow:
first line: I woke up by my neighbor's noise last night.
(a)My neighbor could have had a party last night.
(b)My neighbor could have been having a party last night.
For second sentence, I do not know which one is better.
To an English native, which one do you think is more suitable?
First line- this should be I was woken up
(b) is probably better, though it implies that you're not sure whether your neighbour was having a party or not, and if the noise was loud enough to wake you up, you'd probably know.