The English language isn’t what it used to be.

Migration, colonisation and trade encourage the borrowing and stealing of foreign words and phrases; internationalised stylistic choices seek common ground with speakers of multiple dialects. New technologies require new ways to discuss them, rendering older terms irrelevant. Moral standards change, meaning some euphemisms are no longer needed, while new ones arise.

Then there is spelling. Before the Great Vowel Shift between 1350 and 1700, ‘mice’ rhymed with ‘geese’, and Hamlet’s soliloquy would have sounded like, ‘To bae or not to bae?’ Standardised spelling was slow to keep pace with pronunciation. And the seventeenth and eighteenth centuries saw a custom (but not a rule) to capitalise all nouns.

Some archaic language feels solemn and ritualistic. Oral culture preserves even nursery rhymes and proverbs as sacred incantations; it is no accident that archaisms survive in ceremonial speech, from the Christian ‘With this ring I thee wed’ to the Wiccan ‘So mote it be’. Here, the archaism communicates continuity: a sense that some powers, like magic and marriage, remain unaltered by time.

The amber of jargon, whether legal (‘hereinafter’, ‘habeas corpus’, ‘tort’, ‘forthwith’) or academic (‘disquisition’, ‘cognate’, ‘sine qua non’), also fossilises linguistic inheritances from Greek, Latin and Old French. Lawyers and scholars study and cite older literature, so their archaisms confer the wisdom and authority of tradition.

That is why the internet’s favourite fake archaism, ‘whomst’, mocks the kinds of people who think the more obscure their language, the smarter they will appear. (If ‘whom’ looks smarter than ‘who’, then ‘whomsethsoeveresteth’d’ must be the smartest of all.) ‘Whomst’ also connotes a kind of startled indignation, the sort conspiracy-minded people channel when writing unintelligible but legalistic complaints.

In fiction, archaisms instantly immerse the reader in a story’s historical period. Patrick O’Brian’s beloved Master and Commander novels, painstakingly researched from Napoleonic Wars naval dispatches, are thick with now-unfamiliar colloquialisms and seafaring terms. O’Brian offers the modern reader no quarter; like landsman surgeon Stephen Maturin, they must simply roll with the ship.

Francis Spufford’s 2016 novel Golden Hill harnesses archaisms for a more intertextual purpose. With brio, Spufford adopts mid-eighteenth-century language along with that period’s literary tropes: Golden Hill is the picaresque tale of an innocent abroad in colonial Manhattan, with an unreliable narrator and the contrivance of a twist in the tale. It is immensely vivid, and as light as a whipt Syllabub.

I angst when I am writing historical fiction, vetting my word choices with Google Ngram Viewer, an online tool that tracks the frequency of a word or phrase through a digitised language corpus over time. My goal is to wear lightly a vast amount of pedantic historical fidelity.

But whomst kid I? Language is always a palimpsest; there is no real ‘authenticity’ in summoning the past. Writing at the Oxford Dictionaries blog, Tim William Machan, author of What Is English? And Why Should We Care?, points out that JRR Tolkien’s determinedly archaic vocabulary and syntax in The Lord of the Rings doesn’t evoke medieval literature itself, but rather the Victorian and Edwardian medievalist revival that produced the historical novels Tolkien read as a youth.

Even back then, two nineteenth-century authorities on medieval Norse literature, Gudbrandur Vigfusson and Frederick York Powell, prefaced their translations by deploring the ‘affectation of archaism’ as a ‘grave error’ and an ‘abominable fault’ that makes the originals ‘sound unreal, unfamiliar, false’.

Perhaps, Machan suggests, Tolkien sought to harness precisely this sense of unreality for his fantastical world. Similarly, Paul Kingsnorth created an imaginary hybrid of Old and Modern English for his 2014 novel The Wake, which is set after the Norman invasion of 1066: ‘when i woc in the mergen all was blaec though the night had gan and all wolde be blaec after and for all time.’

What annoys me is when archaisms feel indiscriminately deployed to create a hamfistedly ‘old-fashioned’ atmosphere. This is colloquially known as ‘forsoothery’ or ‘gadzookery’. You will often find it in such cosy confections as ‘Ye olde shoppe’ and the smarmy ‘Methinks, m’lady’ cod-chivalry of pickup artists: inescapably modern ideas that read as inescapably phony.

Some archaisms feel risibly stilted. As young adults, my friends and I would mock the pomposity of high-fantasy fiction, declaiming to one another: ‘Then stood the Master, Tarsharsharsharshar.’

And I actually threw the steampunk paranormal romance Soulless by Gail Carriger across the room in a rage at tortured phrases, including ‘Certainly, most daylight folk wouldn’t peg her as anything less than a standard English prig’ and ‘There must be plenty of discerning gentlemen who’d cop to her value’.

Perhaps fanciful quaintness is all a reader of escapist fiction wants. As a child I loved fairytales and fantasy; the weirdness of their language added to their mysterious allure.

But the best contemporary archaisms don’t just deploy the language as empty picturesque; they also understand and reanimate everything that language meant: lost habits, lost jokes, lost taboos, lost critiques. What therefore Time hath put asunder, let Scriveners join together.