[Magdalen] Rule Britannia.

[M J [Mike] Logsdon]

>>>Then you, he, she, it, & they matched with "will" for simple future,  and
matched with "shall" for insistent future.<<<

I sort of learned this at work a few years ago when we were revising our standard conditions of approval.  "The applicant shall..." is how they all go.  I asked, "Why not 'must'? We're telling them what they 'must' provide in order to meet the condition."  My boss, a non-linguist but a fellow who will always say I taught him more about grammar and writing than many of his past teachers, said "But 'must' is a static thing, don't you think? 'This must happen', even with a 'before' after it implies no sense of timeliness, of urgency, as it were. 'The applicant shall do this or that' implies 'You want a project? You shall step up to the plate then, etc."

I couldn't find a thing wrong with his thinking.