Development of diphthongs

OE possessed a well developed system of diphthongs: falling diphthongs with a closer nucleus and more open glide arranged in two symmetrical sets – long and short: [ea:], [eo:], [ie:] and [ea], [eo], [ie]. Towards the end of the OE period some of the diphthongs merged with monophthongs: all diphthongs were monophthongised before [xt], [x’t] and after [sk’]; the diphthongs [ie:], [ie] in Late WS fused with [y:], [y] or [i:], [i]. In Early ME the remaining diphthongs were also contracted to monophthongs: the long [ea:] coalesced (united) with the reflex of OE [ǽ:] – ME [ε:]; the short [ea] ceased to be distinguished from OE [æ] and became [a] in ME; the diphthongs [eo:], [eo] – as well as their dialectal variants [io:], [io] – fell together with the monophthongs [e:], [e], [i:], [i]. As a result of these changes the vowel system lost two sets of diphthongs, long and short. In the meantime anew set of diphthongs developed from some sequences of vowels and consonants due to the vocalization of OE [j] and [γ], that is to their change into vowels. In Early ME the sounds [j] and [γ] between and after vowels changed into [i] and [u] and formed diphthongs together with the preceding vowels, e.g. OE dæз > ME day [dai]. These changes gave rise to two sets of diphthongs: with i- glides and u- glides. The same types of diphthongs appeared also from other sources: the glide -u developed from OE [w] as in OE snāw, which became ME snow [snou], and before [x] and [l] as in Late ME smaul and taughte.

3.

New phonemes: voiced fricatives /ð/, /v/, /z/

The situation in OE

o voiced fricatives were just allophones of voiceless fricatives

o fricatives were voiceless unless they were between voiced sounds

§ [ð]: oðer

§ [v]: hlāford, hēafod, hæfde

§ [z]: frēosan, ceōsan, hūsian

A number of factors promoted the phonemicization of voiced fricatives:

o loanwords from French: vine (fine), view (few), veal (feel)

o but French lacks interdental fricatives or (with a few exceptions) word-initial /z/

o dialect mixing:

o (fox), vixen: southern English dialects

o loss of final (vowels in) unstressed syllables

o OE hūsian [z] -> -> ME house, hous /z/ (cf noun hous /s/)

o “voiced consonants require less energy to pronounce”: previously unvoiced fricatives became voiced in words receiving little or no stress in a sentence, like function words:

o e.g. [f] of -> /v/

o e.g. [s] in wæs, his -> /z/

o e.g. [θ] in þæt -> /ð/