I'm trying to understand the grammar of this sentence. As far as I understand it, while in this situation is a temporal conjunction and denotes simultaneity.
Quirke's CGEL says this:
While and the less frequent whilst require that their clause must be durative, but the matrix clause need not be:
They arrived while I was sunbathing.
He cut himself while shaving.
So why is 'he listened' not in progressive? Or is progressive not the requirement, and just a durative verb would do?
Am I right to understand "listened" as a temporal frame for "smiling", and that it denotes a complete event during which something was happening?
Huddleston's CGEL says:
Perfective aspectuality does not exclude duration (perfectivity is not limited to achievements), but it does not express duration, hence does not focus it. The progressive, by contrast, does highlight the duration . . . Where two situations are of the same duration and simultaneous, it is possible to use the progressive for either, both, or neither.
Are these two the same thing, then?
He was smiling while he was listening to the story.
He was smiling while he listened to the story
Is there's a noticeable difference between them?
If anyone could help me understand it and maybe point to the right pages in these books, I'd be very grateful.