Great Vowel Shift

The Great Vowel Shift was a series of pronunciation changes in the vowels of the English language that took place primarily between 1400 and 1700 (the 15th century forming the transition period from Middle English to Early Modern English), beginning in southern England and having influenced effectively all dialects of English today. Through this extensive vowel shift, the pronunciation of all Middle English long vowels altered. Some consonant sounds also changed, specifically becoming silent; the term Great Vowel Shift is occasionally used to include these consonantal changes. The standardization of English spelling began in the 15th and 16th centuries; the Great Vowel Shift is the major reason English spellings now often deviate considerably from how they represent pronunciations. Notable early researchers of the Great Vowel Shift include Alexander J. Ellis, in On Early English Pronunciation, with Especial Reference to Shakespeare and Chaucer (1869–1889); Henry Sweet, in A History of English Sounds (1874, revised edition 1888); Karl Luick from Vienna, in a series of works dating from 1892 and Untersuchungen zur englischen Lautgeschichte (1896); and Otto Jespersen (a Danish linguist and Anglicist) who first produced a diagram for it and who in Part I (1909) of A Modern English Grammar on Historical Principles coined the term.