by/until, already/still

Hi, I'd like to ask some questions. Please let me know which are right or wrong plus your kind explanation. The sentences are :

1. It was five in the afternoon when she arrived, but by then the meeting had already been underway.
2. It was five in the afternoon when she arrived, but by then the meeting had still been underway.
3. It was five in the afternoon when she arrived, but until then the meeting had already been underway.
4. It was five in the afternoon when she arrived, but until then the meeting had still been underway.

5. It was five in the afternoon when she arrived, but by then the meeting was already underway.
6. It was five in the afternoon when she arrived, but by then the meeting was still underway.
7. It was five in the afternoon when she arrived, but until then the meeting was already underway.
8. It was five in the afternoon when she arrived, but until then the meeting was still underway.

9. By the time she arrives, they will have already been studying.
10. By the time she arrives, they will still have been studying.
11. Until she arrives home, they will have already been studying
12. Until she arrives home, they will have still been studying.

13. By the time she arrives, they will already be studying.
14. By the time she arrives, they will still be studying.
15. Until she arrives home, they will already be studying
16. Until she arrives home, they will still be studying.

Sorry for presenting all similar sentences in a dull list form. I hope you read them as I want to know the differences among them clearly.

Are these all acceptable in terms of TOEFL grammar?
Are they all acceptably used in real life English?

[Tdol]

1. It was five in the afternoon when she arrived, but by then the meeting had already been underway.

I don'tlike this- try saying 'had already got underway'
2. It was five in the afternoon when she arrived, but by then the meeting had still been underway.

No- 'still' doesn't work here- there's no reason for the idea of persistence here.
3. It was five in the afternoon when she arrived, but until then the meeting had already been underway.

'Until then' would only work if you said something like 'until then they hadn't got down to business'.
4. It was five in the afternoon when she arrived, but until then the meeting had still been underway.

Too many inaccurate time phrases here. I can't see how this one can be repired

5. It was five in the afternoon when she arrived, but by then the meeting was already underway.

Correct
6. It was five in the afternoon when she arrived, but by then the meeting was still underway.

Still doesn't work here- wrong sense.
7. It was five in the afternoon when she arrived, but until then the meeting was already underway.


8. It was five in the afternoon when she arrived, but until then the meeting was still underway.

These both have contradictory timephrases.

9. By the time she arrives, they will have already been studying.
Incomplete- it would work if you dsaid how long they will have been studying
10. By the time she arrives, they will still have been studying.
11. Until she arrives home, they will have already been studying
12. Until she arrives home, they will have still been studying.

None of these work- to use 'by' and then the future perfect progressive, you'd have to say how long. Also, there's no reason to start using 'still' with 'by'.

13. By the time she arrives, they will already be studying.
14. By the time she arrives, they will still be studying.
15. Until she arrives home, they will already be studying
16. Until she arrives home, they will still be studying.



Are these all acceptable in terms of TOEFL grammar?
Are they all acceptably used in real life English?

No, they aren't- you are using things like'still' and 'already' as if they had the same meaning, which they don't.

Thanks for the reply, especially regarding the ill-matching between 'by' and 'still'.

One unexpected thing in your explanation, though, was that you don't seem to care much about whether I used past perfect tense or simple past in the main clause after "by then" and "by the time she arrived". After all, you saw that No.5 sentence is 'correct', but No.1 needs improvement, which makes me dumbfounded.

I thought No.5 sentence is only a informal variation of No. 1, which shows past perfect tense after "by then".

If you compare these two sentences only, which do you prefer to be more grammarically correct?

[juniantara]

No. 5 is the most correct. I think your confusion comes from the word "underway" Things can "be underway" or "get underway" When using past perfect, you use "get." For example:

It was 5 in the afternoon when she arrived, but by then the meeting had already gotten underway.

It was 5 in the afternoon when she arrived, but by then the meeting was already underway.