Vowel Length - Origin

Origin

The long vowel may often be traced to assimilation. In Australian English, the second element of a diphthong has assimilated to the preceding vowel, giving the pronunciation of bared as, creating a contrast with bed . Another etymology is the vocalization of a fricative such as the voiced velar fricative or voiced palatal fricative, e.g. Finnish illative case, or even an approximant, as the English 'r'.

Estonian, of Finnic languages, exhibits a rare phenomenon, where allophonic length variation becomes phonemic following the deletion of the suffixes causing the allophony. Estonian already distinguishes two vowel lengths, but a third one has been introduced by this phenomenon. For example, the Finnic imperative marker *-k caused the preceding vowels to be articulated shorter, and following the deletion of the marker, the allophonic length became phonemic, as shown in the example below. Similarly, the Australian English phoneme /æː/ was created by the incomplete application of a rule extending /æ/ before certain voiced consonants, a phenomenon known as the bad–lad split.

Many long vowels in the Indo-European languages were formed from short vowels and one of the laryngeal sounds, conventionally written h₁, h₂ and h₃. If a laryngeal followed a vowel in Proto-Indo-European, it was usually lost in its later descendants and the preceding vowel became long. However, Proto-Indo-European itself already possessed long vowels as well, usually as the result of older sound changes such as Szemerényi's law and Stang's law.