10. Monophthongs.

Unstressed vowels were weakened and dropped. The changes that occurred to vowels in ME were as follows: Quantitative: Reduction – weakening and disappearance of unstressed vowels. As far as the stress was mainly on the root the vowels in prefixes and suffixes got weak and underwent reduction. In unstressed position only two vowels were left – [ə] and [i]. They had never been contrasted. E.g. ME tale [‘ta:lə], body [‘bodi]. In NE sound [ə] (schwa) was dropped at the end of the words but the letter e was left in spelling to show the length of the preceding vowel. Shortening – all long vowels became short before consonant clusters (except [ld, nd, pt] – before these clusters vowels remained long or if a vowel was short it became long): fīfti- fifty. Lengthening (12^th – 13^th c.) – short vowels became long: before clusters [ld, nd, mb]; in 2-syllable words, only to [e, o, a] in open stressed syllable: open- ōpen. Due to the vocalization of r in the 16-17^th c the vowels before [r] were lengthened (e.g. arm [a:m], for [fo:]). Qualitative: the system of vowels in ME were no longer symmetrical as it was in OE. Short Vowels: [y]-[i] e.g. OE hyll – ME hill (hill); [æ] -[a] e.g. OE wæs – ME was (was). (As a result: i,e,a,o,u). Long Vowels: [ỹ]-[ī]; [ǽ]- [έ]; [ā]-[ō] e.g. OE stān – ME sto[o:]ne (stone). Great Vowel Shift – the change that happened in the 14^th – 16^th c. and affected all long monophthongs + diphthong [au]. As a result these vowels were:

diphthongized; narrowed (became more closed).

[i:] 	[ai]	time [‘ti:mə]	time [teim]
[e:] 	[i:]	kepen [‘ke:pən]	keep [ki:p]
[a:] 	[ei]	maken [‘ma:kən]	make [meik]
[o:]  	[ou] [u:]	stone [‘sto:nə] moon [mo:n]	stone [stoun] moon [mu:n]
[u:] 	[au]	mous [mu:s]	mouse [maus]
[au] 	[o:]	cause [‘kauzə]	cause [ko:z]

This shift was not followed by spelling changes, i.e. it was not reflected in written form. Thus the Great Vowel Shift explains many modern rules of reading: was [was]- was [woz].

11. Dipthongs.

In PG there were no diphthongs. There was just a sequence of two separate vowels. Diphthongs appeared in OE: some (usually long diphthongs) – as a result of merging of two vowels.

Sounds	Diphth.	Gothic	OE
a+ u 	ea:	auso	eare (ear)
e+ u 	eo:	þeudans	þēoden (king)
(i+u)	(io:)	diups	dīop (deep)

Others (usually short diphthongs) – as a result of the influence of the succeeding and preceding consonants (breaking of [æ, e]). In ME OE diphthongs turned into monophthongs:

OE Diphth.	ME S-s	OE	ME
ĭě/īē 	i	līehtan	lighten (lighten)
ĕŏ/ēō 	e	heorte	herte (heart)
ĕă/ēā 	æ	ēast	eest (east)

New diphthongs appeared due to vocalisation of [j], [γ] and [w]. These consonants turned into vowels ([i], [u] and [u] respectively) and became the glides of the new diphthongs. Vocalisation of [r] occurred in the 16^th – 17^th c. Sound [r] became vocalised (changed to [ə] (schwa)) when stood after vowels at the end of the word. New diphthongs appeared: [εə], [iə], [uə]; triphthongs appeared: [aiə], [auə] (e.g. shower [‘∫auə], shire [‘∫aiə]).