section_path: Phonology/Regional variation
section_name: Regional variation
paragraph_text: Regional variation
  
  Varieties of English vary the most in pronunciation of vowels. The best-known national varieties used as standards for education in non-English-speaking countries are British (BrE) and American (AmE). Countries such as Canada, Australia, Ireland, New Zealand and South Africa have their own standard varieties which are less often used as standards for education internationally. Some differences between the various dialects are shown in the table "Varieties of Standard English and their features".
  
  English has undergone many historical sound changes, some of them affecting all varieties, and others affecting only a few. Most standard varieties are affected by the Great Vowel Shift, which changed the pronunciation of long vowels, but a few dialects have slightly different results. In North America, a number of chain shifts such as the Northern Cities Vowel Shift and Canadian Shift have produced very different vowel landscapes in some regional accents.
  
  Some dialects have fewer or more consonant phonemes and phones than the standard varieties. Some conservative varieties like Scottish English have a voiceless sound in whine that contrasts with the voiced in wine, but most other dialects pronounce both words with voiced, a dialect feature called wine – whine merger. The voiceless velar fricative sound /x/ is found in Scottish English, which distinguishes loch /lɔx/ from lock /lɔk/. Accents like Cockney with " h -dropping " lack the glottal fricative /h/, and dialects with th -stopping and th -fronting like African-American Vernacular and Estuary English do not have the dental fricatives /θ, ð/, but replace them with dental or alveolar stops /t, d/ or labiodental fricatives /f, v/. Other changes affecting the phonology of local varieties are processes such as yod -dropping, yod -coalescence, and reduction of consonant clusters.
  
  General American and Received Pronunciation vary in their pronunciation of historical /r/ after a vowel at the end of a syllable (in the syllable coda). GA is a rhotic dialect, meaning that it pronounces /r/ at the end of a syllable, but RP is non-rhotic, meaning that it loses /r/ in that position. English dialects are classified as rhotic or non-rhotic depending on whether they elide /r/ like RP or keep it like GA.
  
  There is complex dialectal variation in words with the open front and open back vowels /æ ɑː ɒ ɔː/. These four vowels are only distinguished in RP, Australia, New Zealand and South Africa. In GA, these vowels merge to three /æ ɑ ɔ/, and in Canadian English, they merge to two /æ ɑ/. In addition, the words that have each vowel vary by dialect. The table "Dialects and open vowels" shows this variation with lexical sets in which these sounds occur.