using would + have to in non-conditional sentences

Solution 1:

In a comment, John Lawler wrote:

Would have to is precisely suited to future imaginary situations. The have to part means must, referring to a necessity or obligation imposed by the situation envisaged. Some kind of preliminary phrase, like In the proposed merger, would be understood.

Certainly that is what I would imagine for the setting and situation, but another possibility exists beyond that. That’s because would can also represent habitual past actions, not merely imagined or hypothetical future ones. For example:

With every new project we attempted, project managers would have to organize copywriters, editors, and designers as well as feedback from clients or other stakeholders. As you might expect, we burned through project managers at an alarmingly high rate during those early years.

All modal verbs are complicated, nuanced things which used judiciously, can add far more to an English verb phrase than any simplistically time-based designation can alone describe.

However, no matter what else they are, modals are defective. They have no inflections nor even infinitives. Because they can only be applied to an infinitive, this means they cannot be applied to themselves. This problem finds its solution in the use of periphrastic constructions with non-defective verbs that you can apply not merely inflections to but also modals when you use the replacement phrases in the infinitive.

Have to, pronounced as if it were hafta, is merely the periphrastic replacement of modal must, a rewrite whose sole reason for existence is to apply inflections and modal nuances to it that you couldn’t apply to a modal itself.

You can’t stack modals in standard English, nor inflect them for person or tense or create infinitives or progressives of them either. So you need to rewrite that modal into a periphrastic phrase with normal verbs first to make all that possible:

• was *musting > was having to
• did *must > did have to, had to
• may *must > may have to
• might *must > might have to
• might *did *must > might have had to
• will *must > will have to
• would *must > would have to

The same thing happens with can converting into something that can hold tense or person markers or other inflections or modals:

• was *canning > was being able to
• did *can > was able to, were able to
• may *can > may be able to
• might *can > might be able to
• will *can > will be able to
• would *can > would be able to

You can stack these up pretty deeply in English for quite a bit of nuance:

Yesterday, he will have had to have been able to call her by three o’clock.

(spoken as) Yesterday he'll've ha't've b'nable t'call 're by three o'clock.

That’s a lot more manageable than this wholly ungrammatical attempt to stack multiple modals:

Yesterday, he (probably / surely / certainly) *did must could call her by three o’clock.

Just don’t ask what “tense” it is. :) These are part of a modal system not a tense system, and because of this they can show much more nuance than simple tense can ever do.

That second, ungrammatical version’s past-tensed verb did indicating the “modal preterite” does make it clearer that it’s something that happened in the completed past than the periphrastic but legal version necessarily may do for learners unused to it — given how it here uses modal will to mean the past not the future! — but the ungrammatical version simply isn’t legal so you have no choice.