LOSS OF VOWEL QUALITY IN UNSTRESSED SYLLABLES

Beginning in the Old English period and continuing in Middle English, most short vowels in unstressed syllables lost quality, converging on the midcentral short vowel /'/. Thus, in unstressed syllables,

OE /a/
>
ME /'/
OE /e/
>
ME /'/
OE /o/
>
ME /'/
OE /u/
>
ME /'/.

 

The short vowel OE /i/ in general remained in unstressed syllables as ME /I/.

In Present-Day English, virtually all unstressed vowels are either /'/ or /I/.