A vowel shift is a systematic sound change in the pronunciation of the vowel sounds of a language.
The best-known example in the English language is the Great Vowel Shift, which began in the 15th century. Other examples of ongoing vowel shifts are the Southern vowel shift in the southern United States, the California vowel shift in California English, or the Northern cities vowel shift in Michigan, Chicago, and parts of upstate New York. The Greek language also underwent a vowel shift near the beginning of the Common Era, which included iotacism. Among the Semitic languages, the Canaanite languages underwent a shift in which Proto-Semitic *ā became ō in Proto-Canaanite (a language likely very similar to Biblical Hebrew).
A vowel shift can involve a merger of two previously different sounds, or it can be a chain shift.
Famous quotes containing the words vowel and/or shift:
“Brute animals have the vowel sounds; man only can utter consonants.”
—Samuel Taylor Coleridge (1772–1834)
“What is the life of man! Is it not to shift from side to side?—from sorrow to sorrow?—to button up one cause of vexation!—and unbutton another!”
—Laurence Sterne (1713–1768)