2. Vowels under stress

In the ME period a great change affected the entire system of vowel phonemes.

OE had both short and long vowel phonemes, and each of these could occur in any phonetic environment, i.e. they were absolutely independent phonemic units.

As a result of important changes coming into the vowel system in the 10^th – 12^th centuries, the ME vowel system was basically different. While in OE quantity (i.e. length/shortness) was a distinctive phonemic feature, in ME (by the 13^th century) quantity of vowels becomes dependent on their environment – to be exact, on what follows. In some phonetic environments only short vowels can appear, while in other phonetic environments only long vowels can appear.

1. Changes of monophthongs

Three long monophthongs underwent changes in Middle English:

Table 7.2 Long monophthongs

Periods Sounds	OE	ME	NE
ā > ō	stān bāt	stōn bōt	stone boat
æ: > ē	slæ:pan	slēpen	sleep
y: > ī	fy:r	fīr	fire

The rest of the monophthongs retained their original quality, for example:

OE ME

ē < ee tēþēþ teeth

ō < oo tōþōþ tooth

ū < ou ūt out

ī < ii tīma time

Out of seven principal OE short monophthongs: a, e, o, i, u, æ, y – two changed their quality in ME:

[æ] > [a] pæt that

wæs was

[y] > [i] fyrst first

but the rest of the monophthongs remained unchanged, e. g:

tellan tellen

hors hors

sinan singen

putan putten

3.3.2. Changes of diphthongs

One of the most important sound changes of the Early ME period was the loss of

the OE diphthongs and the growth of new diphthongs. OE possessed a well developed

system of diphthongs. Towards the end of the OE period all the diphthongs were contracted (i.e. became monophthongs).

Table 7.3

Table 2.

Development of Old English diphthongs in Early Middle English

Periods Sounds	OE	ME
ēo > ee	dēop	deep
ēa > ee	brēad	bread
eo > e	seofon	seven
ea > a	eald	ald

As a result of these changes the vowel system lost two sets of diphthongs, long and short. In the meantime a new set of diphthongs developed from some sequences of vowels and consonants due to the vocalization of OE [j] and [γ], (i.e. to their change into vowels).

Table 7.4

Growth of new diphthongs in Middle English

Change illustrated	Examples
OE ME	OE	ME	NE
e + j ei ei ai au ou ou a	we	wey [wei]	way
e: + j ei	rē	grey [grei]	grey
æ + j ai	mæ	may [mai]	may
a + γ au	lau	lawe ['lauə]	law
o + γ ou	boa	bowe ['bouə]	bow
a: + w ou	cnāwan	knowen ['knouən]	know
a: + x au + x	brāhte	braughte ['brauxtə]	brought

Thus in ME there appeared four new diphthongs: [ai], [ei], [au], [ou]. In addition to the diphthongs which developed from native sources, similar diphthongs. – with i- and u-glides – are found in some ME loan-words, e.g. [i] in ME boy, joy, [au] in ME pause, cause ['pauzə, 'kauzə]. The diphthong [au] occurred also in French borrowings before a nasal, in imitation of Anglo-Norman pronunciation, e.g. ME straunge.

The newly formed ME diphthongs differed from the OE in structure: they had an open nucleus and a closer glide; they were arranged in a system consisting of two sets (with i-glides and with u-glides) but were not contrasted through quantity as long to short.