Professor Barleygrow paces across the well-worn carpet of his office. “This is what linguists like you don’t understand,” he growls to his colleague, gesturing at charts pinned to his wall. — “It's clearly social forces at play!”
The charts show how English sounded radically different in the Middle Ages from how it sounds today. Barleygrow stares at the charts without speaking, seemingly on the verge of a breakthrough. But it is not to be.
Defeated, he sits down on a threadbare chair and continues his rant, “The English language wouldn’t completely change how its vowels were pronounced without some… motivating factor! The Black Death, class consciousness, the influence of the French — one of these has to have been the culprit. I just can’t figure out which one!”
His colleague shakes her head. “A mass of overcomplicating factors. Typical for you, Barleygrow, really. Can’t you see? It’s nothing but the oh-so-predictable effect of one sound change triggering another, and then another, and so. Have you never played the game with dominoes? You tip one over and then they all fall. Click, click, click…”
“Dominoes, indeed!” He turns to the window to hide his pout.
Now, our dear grumpy, domino-deprived Professor Barleygrow is a fictional character, but the mystery he puzzled over is a real one, one which linguists have wrestled with for many years: what caused the Great Vowel Shift?
The Great Vowel Shift was a dramatic change in the pronunciation of the English language occurred between 1400 and 1650, which transformed how English speakers pronounced many of the language’s vowels. The change was so significant that it marks the boundary between Middle and Modern English.
I’ve explored elsewhere how the Great Vowel Shift worked. But, like Professor Barleygrow, some of you have asked why the Great Vowel Shift occurred.
And you’re in good company: scholars, too, have wondered this for decades. Did this massive sound change arise from external social forces, or was it simply the result of the internal mechanics of language itself?
Plague and prestige
To begin to answer this question, I’d like to take you back to London in the mid-14th century. The city has been devastated by the Black Death, the plague that wiped out as much as 50% of England's population.
In 1300, the capital was home to 100,000 people. Just 50 years later, in 1350, only 50,000 remained. It was desperate for new bodies to come and fill its workshops, markets, and guilds.
And come they did, in droves. Peasants and artisans from the Midlands and eastern counties, speaking a variety of regional dialects, flocked to the city, and London's population began to swell again. Between 1350 and 1500 the population of London doubled thanks to these newcomers, returning to pre-Black Death levels. By 1600 it had doubled again, to 200,000 people. By 1700, it had shot up to 600,000 people.
But these weren't just any immigrants. Many were ambitious craftspeople and merchants, eager to improve their standing in the magnet that was medieval London. This social climbing may be the key to understanding the Great Vowel Shift.
When people try to move up the social ladder, they often change their speech to match what (they think of as) the prestigious accent. But they often overshoot the mark.
In the London of the late Middle Ages, this process went into overdrive. The city had become a melting pot of dialects from different parts of England. At the same time, the English language was rising in status. Where it was once less prestigious than French, it was quickly becoming a respectable language once again. Socially mobile immigrants were eager to sound like real Londoners rather than people who had just arrived from the provinces, so they started exaggerating certain quirks of speech they associated with the upper classes.
For example, a newcomer to London hear might hear the locals pronounce the word name pronounced slightly differently than in their hometown. But in their eagerness to avoid sounding like they don’t belong, they newcomers might overcompensate. So if they perceive their pronunciation is made too far back in the mouth, sounding a bit like “nahm”, they they may overcompensate and say “nehm” to make abundantly clear that they are not country bumpkins.
Inadvertently, however, they’re setting a new standard, one that would eventually lead to the modern pronunciation of name.
But what’s really interesting is that they created something entirely new, rather than simply mimicking an existing standard. This phenomenon of hyperadaptation isn't unique to medieval England. Even today, linguistic innovations often emerge from groups striving to improve their social standing.
For example, someone from a working-class background who enters an elite university or profession today might consciously modify their accent. But if their “posh radar” isn’t perfectly tuned, they can overshoot and end up sounding even posher than someone who had been born into privilege.
This same dynamic, played out across an entire speech community, could have big effects — even as big as the Great Vowel Shift.
Can we blame the French?
The hyperadaptation theory also sheds new light on the complex relationship between English and French during this period.
By the early 1400s, the English aristocracy had largely abandoned French as their primary language. But French still carried enormous prestige — and remained the language of refinement, diplomacy, and high culture. (In some respects, it still does to this day!) This created a situation where English speakers, particularly those with social aspirations, were hyper-aware of French linguistic influences.
For example, the aristocracy in the late fourteenth and fifteenth centuries may have adopted distinctive pronunciations of French-derived words as a way of distancing themselves from the lower classes. They pronounced these words with the vowels higher in the mouth (in a more “French” way), which socially ambitious newcomers noticed. The French-derived word agree, for instance, could have been pronounced in one of two ways: a way that emphasized its Frenchness and a way that didn’t. The more French-sounding variant was the more prestigious pronunciation.
These newcomers then imitated the more prestigious, more French-sounding forms, sometimes pushing other sounds even further to maintain clear distinctions — more on this in a minute.
In this case, there needn’t be any conscious imitation of French. Rather, patterns that were already around in English — at least in some dialects — gained prestige because they sounded more “refined” because they reminded people in some way of French, or at least of élite English-speakers who spoke French.
If the hyperadaptation theory is correct, the Great Vowel Shift looks less like the single change it appears (in retrospect) to be, and more like the sum of many thousands of small adjustments made to navigate life in a time of great social change.
The phonetic domino effect
While social forces provide a compelling explanation, many linguists maintain that no such explanation is required: for them, the Great Vowel Shift was driven primarily by the internal mechanics of language itself.
Here’s how this kind of explanation works: the vowels of a language often move in tandem. This happens because a single vowel is often the only difference between several words (think of bit, bet, but, bait, beat, boat…). So if one vowel changes its pronunciation, others often change too, in order to preserve these contrasts. And this triggers a change in another vowel, and so on.
In other words, the vowels are like a set of dominoes set up in a row. A change in one triggers a change in the next, which triggers a change in the next, and so on, until the last domino has fallen.
This “domino” theory — the term linguists use is chain shift — doesn’t appeal to complex social motivations. All it needs is the natural tendency of languages to maintain clear distinctions between sounds.
Interestingly, the changes of the Great Vowel Shift show a kind of symmetry. The vowels made in the front of the mouth, i and e, and the vowels made towards the back, o and u, shifted in parallel. This maintained the vowel system as a whole, even as the individual sounds in the system underwent dramatic change.
The two explanations are not mutually exclusive. The initial changes may well have been caused by social factors, and then, the domino effect took over from there to make it a change that effected the whole system. Hyperadaptation simply provided the first push.
An unsolved mystery in every other word
What’s fun about the Great Vowel Shift is that its effects are so pervasive that it’s hard to say an English sentence without pronouncing one of the affected vowels. Virtually every time you open your mouth (not “mooth”), you’re carrying on the legacy of a transformation whose origins still provoke debate, especially among scholars like Professor Barleygrow.
Not to play the “wise middle ground” card, but I think a combination of factors really is the most convincing. Language is, after all, both a social and a biological phenomenon: languages are shared and moulded by group dynamics, but it relies on human mouths, ears, and minds to transmit itself.
Someone like our Professor Barleygrow might call it “the greatest unsolved mystery in English philology.” It’s likely that the mystery will remain unsolved. Whatever the answer truly is, the search for the cause of the Great Vowel Shift is a good reminder that languages are living things, and their life histories often defy a simple explanation.
"Can we blame the French?"
Silly Colin, it doesn't matter if we *can* — we most certainly will, regardless!
Great article, as always 😉
Great post, Colin. I have a question about accents. Why don't Americans and Canadians sound like Aussies and Kiwis?