The Great Vowel Shift and Move Towards Modern EnglishDuring the 15th, 16th and 17th centuries a radical change in pronunciation began to take place in the English language. Transforming Middle English into a form of early Modern English. This was the result of vowel sounds being made higher and further forward in the mouth, with shorter vowel sounds mostly unchanged, and the transition happening slowly between 1400 and 1700. A lot of languages undergo vowel shifts, but none as quickly as the English vowel shift in linguistic terms. The purer vowel sounds that had been used by most European languages, and phonetic pairings of long and short vowel sounds, were gradually disappearing, and this took place within a century or two.