So you can use "quasi" in a temporal sense?
To me "era quasi morto" sounds like "he was almost dead" (condition) as opposed to "he almost died" (temporal). I'm not sure if I can give a proper explanation of the difference.
neutrino2, thank you, but I'm not familiar with the expression "stare per morire" and I couldn't find a translation on the internet. Maybe you're right..
As I understand, "stare per morire" seems to be very close to "being about to die", which would capture the temporal aspect of the sentence. But if "essere quasi morto" sounds more natural, I guess I'll stick with that version.