Scottish vowel length rule
The Scottish vowel length rule, also known as Aitken's law, describes how vowel length in Scots, Scottish English, and, to some extent, Ulster English and Geordie is conditioned by the phonetic environment of the vowel. Primarily, the rule is that certain vowels (described below) are phonetically long in the following environments:
- Before /r/.
- Before a voiced fricative (/v, z, ð, ʒ/).
- Before a morpheme boundary.
- In a word-final open syllable, save for the HAPPY vowel /e/ (or, in Geordie, /iː/).
Exceptions can also exist for particular vowel phonemes, dialects, words, etc., some of which are discussed in greater detail below.