In OE stress usually fell on the first syllable of the word, rarely on its second syllable. Word stress in OE was fixed: it never moved in inflection and seldom in derivation. This way of word accentuation was considerably altered in the succeeding periods. The word accent acquired greater positional freedom and began to play a more important role in word derivation. These changes were connected with the phonetic assimilation of thousands of loan-words adopted during the ME period. Gradually, as the loan-words were assimilated, the word stress was moved closer to the beginning of the word. It is known as the “recessive” tendency, e.g. vertu [ver´tju:] became NE virtue [və:t∫ə]. In words of three or more syllables the shift of the stress could be caused by the recessive tendency and also by the “rhythmic” tendency. Under it, a secondary stress would arise at a distance of one syllable from the original stress. Sometimes the shifting of the word stress should be attributed not only to the phonetic tendencies but also to certain morphological factors. Thus stress was not shifted to the prefixes of many verbs borrowed or built in Late ME and in Early NE, which accords with the OE rule: to keep verb prefixes unstressed, e.g. present. Corresponding nouns sometimes received the stress on the first syllable: NE ΄present n - pre΄sent v; ΄discord n - dis΄cord v. The latter pairs of words show that the role of word accentuation has grown: word stress performs a phonological function as it distinguishes a verb from a noun.
In Early ME the pronunciation of unstressed syllables became increasingly indistinct. As compared to OE, which distinguishes five short vowels in unstressed position [e/i], [a] and [o/u], Late ME had only two vowels in unaccented syllables: [ə] and [i], e.g. OE talu – ME tale [΄ta:lə] – NE tale, OE bodiз – ME body [΄bodi] – NE body. The final [ə] disappeared in Late ME though it continued to be spelt as -e. When the ending –e survived only in spelling, it was understood as a means of showing the length of the vowel in the preceding syllable and was added to words which did not have this ending before, e.g. OE stān, rād – ME stone, rode [´stone], [´rode] – NE stone, rode. It should be remembered that while the OE unstressed vowels thus were reduced and lost, new unstressed vowels appeared in borrowed words or developed from stressed ones, as a result of various changes, e.g. the shifting of word stress in ME and NE, vocalization of [r] in such endings as writer, actor, where [er] and [or] became [ə].