Canadian Raising

Canadian raising refers to either of two similar sound changes that occur in a number of North American varieties of the English language, in which certain diphthongs are "raised" before voiceless consonants (e.g., /p/, /t/, /k/, /s/, /f/). The first variant, "classic" Canadian raising, occurs largely in Canadian English and in certain nearby areas of the northern United States, and affects both /aɪ/ and /aʊ/. This results in the stereotypical Canadian pronunciation of about as "aboot". A second variant with a much larger distribution across many parts of the United States affects only /aɪ/, and results in differing pronunciations of the first vowel in the words rider and writer.

The raised variant of /aɪ/ typically becomes, while the raised variant of /aʊ/ varies by dialect, with more common in the west and a fronted variant commonly heard in Central Canada. In any case, the -component of the diphthong changes from a low vowel to a mid-low vowel (, or ).

Those speakers with either variant will pronounce the words rider and writer as and, respectively, while those speakers lacking the change entirely will pronounce both as . (In Received Pronunciation in the United Kingdom, these words would be pronounced and, respectively.) This phenomenon preserves the recoverability of the phoneme /t/ in "writer" despite the North American English process of flapping, which merges /t/ and /d/ into before unstressed vowels.