The Middle English and the Modern English Periods

a: > ei; : > e: > i:; i: > ai; : > ou; o: > u:; u: . au.

If we compare the system of long vowels of the pre-Great Vowel Shift period with the system of the post Great Vowel Shift period, we have to state that there appeared no new vowels, that is the Great Vowel Shift did not result in any new vowels. So we should rather speak of rearrangement of long vowels:

Middle English	New English
[ei] wey	[ei] make
[i:] time	[i:] see
[e:] seen	[i:] sea
[ai] sayde	[ai] time
[ou] howe	[ou] go
[u:] hous	[u:] moon
[au] drawen	[au] house

At the same time the essence of this phonetic change consists in the fact that the distribution of the long vowels became different: the sound [i:] occurs in the New English word see which was pronounced as [se:] in Middle English, but the same sound does not occur in the new English word time which was pronounced as [ti:m ] in Middle English. The Great Vowel Shift was the most profound and comprehensive change in the history of English vowels. Every long vowel, as well as some diphthongs, was "shifted", and the pronunciation of all the words with these sounds was altered. The problem of the Great Vowel Shift has attracted the attention of many linguists and still remains unsolved.