Compensatory lengthening

Compensatory lengthening in phonology and historical linguistics is the lengthening of a vowel sound that happens upon the loss of a following consonant, usually in the syllable coda, or of a vowel in an adjacent syllable. Lengthening triggered by consonant loss may be considered an extreme form of fusion (Crowley 1997:46). Both types may arise from speakers' attempts to preserve a word's moraic count. An example from the history of English is the lengthening of vowels that happened when the voiceless velar fricative /x/ and its palatal allophone [ç] were lost from the language. For example, in the Middle English of Chaucer's time the word night was phonemically /nixt/; later the /x/ was lost, but the /i/ was lengthened to /iː/ to compensate, causing the word to be pronounced /niːt/. (Later the /iː/ became /aɪ/ by the Great Vowel Shift.) Both the Germanic spirant law and the Ingvaeonic nasal spirant law show vowel lengthening compensating for the loss of a nasal. Non-rhotic forms of English have a lengthened vowel before a historical post-vocalic */r/: in Scottish English, girl has a short /ɪ/ followed by a light alveolar /r/, as presumably it did in Middle English; in Southern British English, the */r/ has dropped out of the spoken form and the vowel has become a "long schwa" [əː]. Compensatory lengthening in Classical Hebrew and Aramaic is dependent on the class of consonant which follows the prefix (definite article in Hebrew and prefix waw-hahipukh in both languages). E.g. (using the Hebrew definite article [hey with pataḥ plus dagesh in following consonant]): Before and it is usually [hey with qametz]. Before and it is usually [hey with pataḥ]. If it is pretonic it may be [hey with qametz]. But when it is propretonic, whatever the guttural, it will usually be [hey with segol]. Compensatory lengthening is very common in Ancient Greek. It is particularly notable in forms where n or nt comes together with s, y (= ι̯), or i.