Macedonian orthography is phonemic with a correspondence of one grapheme per phoneme. Each vowel phoneme in the table is represented by three symbols. Japonic languages also resemble Ainu and modern Korean in having a single liquid consonant phoneme. A sequence of graphemes representing a phoneme is called a polygraph. First, interchanged allophones of the same phoneme can result in unrecognizable words. The most frequent consonant phoneme is , the rarest is . Middle Korean had an additional vowel phoneme denoted by , known as (literally "lower a"). Up-gliding is a diphthongized vowel sound, , used as the pronunciation of the phoneme . The voiceless realization of the phoneme is velar . The above shows that in English, and are allophones of a single phoneme . Ikema Miyako has a voiceless nasal phoneme . The Cyrillic alphabet avoids such ambiguity by providing a single letter for each phoneme&colon; . Arguably, the diphthongs and are also part of the phoneme set. This restricted variation has prompted several authors to postulate a single rhotic phoneme. Cairene also has as a marginal phoneme from loanwords from languages other than Classical Arabic.