not sure about the textbook version...though there might be something.

"Now is the winter of our discontent"

- that is a good example.

I suspect the discrepancy is that between spoken English in his time and presently...

or perhaps the "mood" of the thing...

in our language today, "now" tends to be used aggressively, as a kind of command or immediacy..

I suspect in today's English the phrase, in terms of meaning could be more clearly written...

"and then came the suffering..."

where "Now" is not so striking or hard or quick...but a subtle movement forward...the way we might use a pause or hesitation, rather than a direction or command...

Shakespeare is probably the single most complex poet on the planet...ever. Plus, again, even though it is English, it is a very different English than modern English. It is only a few hundred years after Chaucer...and his English...which was closer to modern German, than to modern English.

So, if you want to write in a formal style and experiment with meter and such, I would focus on modern work, in which the English used is that with which you are already familiar. Then, there should be less confusion.

Maybe work with Dickinson, Emerson and Whitman. Their English is American English, reasonably modern and yet more formal in structure than most of the poems written today.