Quantitative changes of vowels in OE and ME
At the end of OE and in the immediately succeeding centuries accented vowels underwent a number of quantitative changes which affected the employment and the phonological status of short and long vowels in the language. In OE quantity was the main basis of correlation in the vowel system: short vowels were phonemically opposed to long ones, roughly identical in quality. In later OE and in Early ME vowel length began to depend on phonetic conditions.
The earliest of positional quantitative changes was the readjustment of quantity before some consonant clusters;it occured in Early ME or perhaps even in Late OE.
1) Short vowels were lengthened before two homorganic consonants, a sonorant and a plosive; consequently, all vowels occuring in this position remained or became long e.g. OE wild-- ME wild [ wi:ld] ( NE wild);
2) All other groups of two or more consonants produced the reverse effect: they made the preceding long vowels short- and henceforth (vpred') all vowels in this position became or remained short, e.g. OE cepte- ME , kepte['kcpte] ( NE kept).
3) Short vowels became long in open syllables. This lengthening mainly affected the more open of (,he short vowels[e], [a] and fob but sometimes, though very seldom, it is also found in the close vowels it] and [u).
In order to achieve an average uniformity in the length of the syllable, and also to use an average amount of energy for its pronunciation, the vowel was shortened before a group of consonants and was made longer of the were consonants following, that is , in "open" syllables. Lengthening of vowels before homorganic groups looks as an exception or a contradiction, to account for this lengthening it was suggested that - nd, -ld and the like were virtually equivalent to single consonants, therefore a long vowel would not make the syllable too heavy.
Qualitative changes of vowels in Mid E.
In mid E. the pronunciation of short vowels in unstressed syllables became increasingly indistinct. If in OE any short vowels could occur in unstressed position in late ME only 2 new vowels ə and I could be found there. And even these 2 vowels were not directly contrasted in unstressed vowels had been practically lost. Thus in OE where is the morphological forms of the verb could be differentiated through their endings, which leveled under one and same endings in the late English (sunu, suna – sone сын). From the phonetic point of view these change indicate a decisive separation of unstressed vowels from stressed ones. While in OE there was no principal difference in the quality of vowel phonemes stressed or unstressed syllables in Mid.E there developed a very significant difference n this respect: all unstressed vowels weakened or reduced to e. This was not only phonemic change it had also far reaching morphological consequences. The short OE æ was replaces in ME by the back vowel à (wæ – was). In the ME the vowel ý was diabolized and it produced various results depending on dialect y, y: - i, i: (east-midland, northern), u, u: - (west-midland, south-western), e, e: - (southern, former Kentish). F.e cysan- kissen, kussen, kessen. Modern literary English comprised the words of various dialects, that underwent the process of delabilazation of y during ME. (mycel-much, lyft-left, blyscan-blush). But at the same time there are several reflecting cases of compromise between 2 different dialects in spelling and pronunciation of same words. Thus the spelling of the word busy reflects the west-midland dialects while its pronunciation is influenced by the east-midland dialect. In the similar way the history of the verb “ to build” bears the features of east and west-midland dialects.
Vocalization of fricatives.
During the ME period all English diphthongs turned into monophthongs and thus the OE system of diphthongs disintegrated, but parallely in the same period a group of new diphthongs was developed having as a resource vocalization of fricatives y, y’, x, x’. In OE the first pair was spelt through the letter з, the second pair – through the letter h, but in ME the diagraph h was introduced to reflect x, x’. Of these 3 fricatives 2 were palatal x’, y’, the palatal fricatives in combination with a preceded vowel yielded diphthongs in i, and velar fricatives yield in u. It is supposed that palatal x’, y’ were the first to be involved into the process of vocalization: the first of them began to vocalize in OE, the second x’ in the beginning of the ME. The OE combination æy’ developed in the ME into the diphthongs ai and ey’ – ei (dæg-dai) in ME texts there can be found the cases of the intermediate state of vocalization reflected in spelling mæig, dæiз. Here the weakened palatal y’ is preceded by the newly developed vocalic glide i. it should be mentioned that the diphthong ai and ei were very similar to their phonetic features and soon they merged, which explains modern pronunciation of the words: say, day, lay, may. Originally, they had the diphthong ai. The palatal fricative x’ usually occurred after the close vowel I together with which it didn’t produce a diphthong but a long monophthong i: (cniht-kniht, knixt-kni:t). Even if x’ occurred open vowels the final results of its vocalization through the gradual stage of it’s development was the same (heah-heihhigh(hi: )). Non palatal fricatives x, y were usually preceded by Λ or o. after their vocalization there developed 2 diphthongs: au and ou (ay-aw-au, oy-ow-ou). Here again the intermediate stage of vocalization of y into u, which was w (drayan-drawen-drauen). If y was preceded by the close u, vocalization resulted in the development of the long monopthong u: (fluyol-flu:l). velar y could be vocalized after l, r (boryah-borəu). the vocalized fricatives x together with the preceding vowel produced diphthong au and ou (brohte-broute). Of the 4 fricatives above mentioned x was the latest to be vocalized and it’s change was not of a universal character. Alongside u glide serving as the second element of the diphthong au, ou it could also developed into another fricative which was f (laugh, rough, enough) or remanded unchanged. Thus, during the OE period the OE system of diphthong was superseded by a new system. OE diphthongs of the ea or eo type had the second element open or half open, while in the new diphthong of the ai or au type it was close. Thus, numerous qualitative and quantitative changes of the ME period affected all kinds of vowel phonems. In the process of these changes short vowels tended to became wild and long vowels-narrow. All OE diphthongs became monothongs. Instead on the bases of vocalized fricatives a new system was developed. These new diphthongs were: ai, ei, au, oy. In ME vowel length lost its phonemic value and as a result a strickt system of long and short vowels disappeared. The system of ME monophthongs appeared.
Middle English dialect.
During the ME period the whole system of OE vowel suffered considerable changes either quantitative or qualitative. Quite often these changes had dialectal peculiarities. In ME old-English dialects regrouped in accordance with their geographical position. There were the fallowing essential groups: the northern dialects : it had developed from OE Northumbrian dialect. In ME it also comprised the dialects from Yorkshire and Lancashire. The midland dialect: they had developed from Mercian dialect. It was represented in ME by 2 main areas – east and west midland. The southern dialect: it comprised OE Kentish, west-Saxon, east-sakson dialects. East-Saxon dialect was not important in OE, but it became very important in ME, since it was the part of London dialect and it established its priority over other dialects.