> "By the time I'm going home, the rain shall/will have stopped."
>
> Are both shall/will allowed in current-day BrE, in this context, in all
> registers?
In that sentence, I think it should be "will".
The rules I learnt at school were:
Normal: I shall, you will, he will.
Emphatic: I will, you shall, he shall.
But I think nowadays the difference with the first-person is being eroded
in colloquial speech.
Cheers
Tony

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Tony Mountifield
Work: tony@softins.co.uk - http://www.softins.co.uk
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