A series of changes affecting the long vowels of English, known as the Great Vowel Shift, took place in the early 1400s. Before the shift, a word like loud would have been pronounced ‘lood’, name as ‘nahm’, leaf as ‘layf’, mice as ‘mees’. Although the shift had no clear beginning or end, the majority of the changes took place within two generations. Grandparents and grandchildren in 1450 probably had considerable difficulty understanding each other.
