English Language History : What Caused the Great Vowel Shift?

English is arguably the single most important and influential language in today’s world. It does however contain many vagaries and annoying inconsistencies. One of which is the variations of how vowel combinations should be pronounced. For example, the ‘ea’ in ‘bread’ is pronounced the same as the ‘e’ in ‘bred,’ and not the same as the ‘ea’ in ‘break.’



Old English

c500 – c1100



Middle English

c1100 – c1500

Great Vowel Shift


International Trade

Early Modern English

c1500 – c1800

Industrial Revolution


Late Modern English

c1800 – Present



English Today

Present day

These inconsistencies weren’t always there and there was only one way to pronounce each vowel so that before approximately 1300 English pronunciation was much more consistent. The problem arose from something linguistic scholars call ‘The Great Vowel Shift’. Something curious happened in the 14th and 15th centuries when, in little over 200 years, the way we spoke English changed very rapidly indeed. But what could have possibly caused this ?

The History of English : An Overview

Before we look at what could have possibly happened to so alter the way vowels were pronounced lets put this in context to what we know of the development of the English language to date.

The history of the English language has been neatly divded, by modern scholars, into about 5 distinct periods. Of course the language itself has ever been evolving and would have transformed gradually over time so we shouldn’t regard these periods as absolute but see the English language as a spectrum of change, morphing gradually over time.

The main phases identified by scholars are : Old English; Middle English; Early Modern English; Late Modern English and English Today.

The Great Vowel Shift

the great vowel shift was a water shed event … and is why most modern day English speakers would struggle to speak with people from the 14th & 15th Centuries

The great vowel shift was a water shed event , so much so that it is the reason that why most modern day English speakers would struggle to speak with people from the late 14th & 15th Century.

The ‘vowel shift’ relates to the sound of long vowels. For example, a word like “goose” would have been pronounced “goas” (oa as in boat) in the 15th century and it would not be pronounced “goos” until sometime in the 16th century. “mice” would have been pronounced “mees”, “house” –“hoos”; “name” — “nahm”, “feet” — “fayt” (ay as in “pay”), etc. The language was in a radical shift during the 15th century and into at least the middle of the 16th century.

Possible Causes …

Today’s WordPronunciation before the Great Vowel Shift
Goose“goas” (oa as in boat)
House “hoos”
Feet“fayt” (ay as in “pay”)

Rather disappointingly we have to say up front that no one is entirely sure what the actual causes of the vowel shift were. However several very plausible theories exist that attempt to explain it and as with most things in life the real answer is probably a combination of all of them to varying degrees.

Redistribution of Populations

Virulent outbreaks of plague, also know as the ‘Black Death’, in the late 14th and early 15th century saw vast swathes of the population perish and as a consequence a redistribution of populations when people from many different regions emigrated to the southeast of England, where it’s thought that their accents were combined to create new pronunciations based on the standard London vernacular of the time.

The influx of French “loanwords”

Conversely whilst the nobility were beginning to speak English the peasants were having to grapple with an influx of French “loanwords” – no doubt brought in by their noble overlords.

The Mechanism of Change …

Scholars have identified a mechanism for the “The Great English Vowel Shift” as a celebrated instance of what they call a “Chain shift” – a sound change with impacts several sounds one after the other, as a kind of chain reaction.

In Conclusion … No one knows for certain what caused the Great Vowel Shift, but it’s because of these changes during this period that English has so many strange pronunciations. Students who have difficulty pronouncing English words today can blame people who lived in England in the Middle Ages!


What Are the Oldest Words in the English Language Still in Use Today ?
The Evolution of the English Language
How Far Back in Time Could an English Speaker Go and Still Understand the Language ?

Author: Robert

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