Great Vowel Shift

The Great Vowel Shift was a major change in English long-vowel pronunciation, beginning around the fifteenth century and continuing into the eighteenth. It reshaped the relationship between English spelling and sound.

Chain shift: A series of linked sound changes in which one phoneme’s movement creates pressure for others to move. The Great Vowel Shift is commonly analyzed as a chain shift among long vowels.
Middle English: The stage of English spoken and written from roughly the late eleventh to the late fifteenth century. The shift began during the transition from Middle English to Early Modern English.
Phonetics: The study of speech sounds, including how they are produced, transmitted, and perceived. Historical vowel descriptions rely on articulatory and acoustic distinctions.
English orthography: The conventional system for spelling words in English. Much spelling settled before the long-vowel pronunciations reached their modern forms.
Vowel raising: A sound change in which a vowel is pronounced with the tongue higher in the mouth. Many of the shift’s lower long vowels rose toward higher positions.
Early Modern English: The stage of English used from roughly the late fifteenth to the late seventeenth century. Its pronunciation developed while the vowel shift was under way.
Phonology: The study of how speech sounds function and pattern within languages. The shift changed the organization of English vowel contrasts, not just individual pronunciations.
English phonology: The sound system of English, including its vowels, consonants, and patterns of stress. Modern English retains vowel patterns shaped by the historical shift.
Vowel fronting: A sound change in which a vowel is pronounced farther toward the front of the mouth. Front-vowel movements formed part of the changing long-vowel system.
English Reformation: The sixteenth-century religious transformation that established Protestantism in England. Religious and social upheavals coincided with the period in which the shift unfolded.

Linked from 15 pages