An ELT Glossary : Rhotic Accents
Rhotic accents are those where a post-vocalic "r" (ie one occurring after a vowel in the written form) is pronounced. This does not happen in non-rhotic accents.
For example, the words where, hard and butter would be pronounced as /weə/, /hɑːd/ and /bʌtə/ in a non-rhotic accent but as /weər/, /hɑːrd/ and /bʌtər/ in a rhotic accent.
Many N. American accents are rhotic, as are some British accents - eg Scots and Somerset - though most British accents and other varieties such as Australian English are non-rhotic.
A classic work on the phonology of English - updated to reflect modern pronunciation.
Cruttenden, A. (2014) Gimson's Pronunciation of English, Routledge
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