I <played/was playing> tennis while she <read/was reading> a book. (simultaneous actions in the past)

[Michaelll]

Are you asking if this suggests she finished the report?

No. You wrote 'especially the second' which is in the perfect aspect, so I wrote an example where (as I think) the perfect aspect may not mean she finished it.

……13b. While Sally wrote a report, Barry prepared lunch.
……13c. Sally wrote a report while Barry was preparing lunch.

What I can't figure out is this: do I understand correctly that 13a and 13d don't tell us whether the report was completed or not, while 13b and 13c show us that the report was completed?

None of them necessarily mean that the report was completed.

• Barry prepared lunch while Sally wrote the report. If she hadn't written the report, she'd have had time to do something else.

Or another one:
Jack: She prepared lunch while I wrote the report.

• Jack claims to have written the report.

 

[Barque]

No. You wrote 'especially the second' which is in the perfect aspect, so I wrote an example where (as I think) the perfect aspect may not mean she finished it.

Well, I think it (your example from #39) sounds as if she finished it.

The exact words used, the meaning, the surrounding words, all influence the meaning of the overall sentence.

Jack claims to have written the report.

This means the report is a completed one.

 

[Barque]

Barry prepared lunch while Sally wrote a report. If she hadn't written the report, she'd have had time to do something else.

This is the one I was referring to, from post #39. It sounds as if she did finish the report.

However if you'd said "If she hadn't worked on the report ..." it wouldn't have been clear if she'd finished the report or not.

 

[Michaelll]

However if you'd said "If she hadn't worked on the report ..." it wouldn't have been clear if she'd finished the report or not.

But the person saying that may not know whether she finished it or not, right? He just heard that line, and that's it.

A: Barry prepared lunch while Sally wrote the report.
B: If she hadn't written the report, she'd have had time to do (that something).

What I can't figure out is this: do I understand correctly that 13a and 13d don't tell us whether the report was completed or not, while 13b and 13c show us that the report was completed?

13b. While Sally wrote a report, Barry prepared lunch.
13c. Sally wrote a report while Barry was preparing lunch.

None of them necessarily mean that the report was completed.

 

[Tarheel]

But the person saying that may not know whether she finished it or not, right?

No. Not conclusively.

 

[Barque]

But the person saying that may not know whether she finished it or not, right? He just heard that line, and that's it.

I don't understand what you mean by this. You seem to be saying the speaker "heard that line".

 

[Michaelll]

I don't understand what you mean by this. You seem to be saying the speaker "heard that line".

I mean that as you said, "While Sally wrote a report, Barry prepared lunch" doesn't mean that the report was completed #28. So, the person who has heard this line/phrase/sentence, may respond with a counterfactual past using the perfect aspect, which in this case no longer contains the meaning of a completed report (simple logic).

A: Barry prepared lunch while Sally wrote the report. (as Barque said it doesn't mean that the report was completed #28)
B: If she hadn't written the report, she'd ... (anything) (as an example, have had time to call me).

And the same here:
Sally: Barry prepared lunch while I wrote the report.
Later:
Jack: Sally claims to have written the report.

 

[Barque]

So, the person who has heard this line/phrase/sentence, may respond with a counterfactual past using the perfect aspect, which in this case no longer contains the meaning of a completed report (simple logic).

I'm not sure if I've understood you. But if someone told me "Barry prepared lunch while Sally wrote a report" and if I'd wanted Sally to call me, I'd have said "I wish she hadn't had a report to write. I was hoping she'd call me".

 

[Glizdka]

The problem with quizzes such as these ones is that the sentences are way too short to properly determin which tense should be used, could be used, or must be used, especially when the difference is very fine.

I've seen plenty of exercises like these, and they usually have more than one possible answer. While some do show a strong preference towards one of the two options, you can always justify just about anything with enough context.