I'd never heard of this until just now while researching The Canterbury Tales.
Basically, the way vowels are pronounced underwent a radical shift between the time of Chaucer and that of Shakespeare.
It's also one reason why English has so many confusing spellings that can sound the same, ie, "been" and "bean".
Wikipedia has a long and technical explanation of what happened:
Great Vowel Shift - Wikipedia, the free encyclopedia
For non-linguists, here's the simpler explanation of what happened - and why:
The Great Vowel Shift - An Explanation for Kids
I guess now I know why some people say "pasta" and others say "paaaasta" - the change is still happening.
Basically, the way vowels are pronounced underwent a radical shift between the time of Chaucer and that of Shakespeare.
It's also one reason why English has so many confusing spellings that can sound the same, ie, "been" and "bean".
Wikipedia has a long and technical explanation of what happened:
Great Vowel Shift - Wikipedia, the free encyclopedia
For non-linguists, here's the simpler explanation of what happened - and why:
The Great Vowel Shift - An Explanation for Kids
I guess now I know why some people say "pasta" and others say "paaaasta" - the change is still happening.