The Great Vowel Shift

The long/stressed vowels of Old/Middle English:

front		back
i:		u:
e:		o:
ɛ:		ɔ:
	a:

Typical orthography for these was as follows:

i:	y,i	mine,sight
u:	ou,u	house
e:	ee,e,e_e	sheep, me, mete
o:	oo,o	boot
ɛ:	ea,e	break, beak
ɔ:	oa	loaf
a:	aa,a	name

The Great Vowel Shift involved everything moving up a slot:

• i: -> ai
• u: -> au (unless followed by a labial consonant p/b/m)
• e: -> i:
• o: -> u:
• ɛ: -> e: -> i:
• ɔ: -> o:
• a: -> ɛ: -> e: