Rendaku

Rendaku (連濁; Japanese pronunciation: [ɾendakɯ], lit. 'sequential voicing') is a pronunciation change seen in some compound words in Japanese. When rendaku occurs, a voiceless consonant (such as /t k s h/) is replaced with a voiced consonant (such as /d ɡ z b/) at the start of the second (or later) part of the compound. For example, the morpheme kami (paper) starts with the voiceless consonant /k/ when used as an independent word or as the first part of a compound word, but this is replaced with the corresponding voiced consonant /ɡ/ in the compound word origami, from ori (fold) + kami.

Although rendaku is common, it does not occur in all compound words. A rule known as Lyman's law blocks rendaku when the second element already contains a voiced obstruent phoneme (/d/, /ɡ/, /z/, or /b/). For instance, in umikaze (sea breeze), the /k/ in kaze (wind) remains voiceless because /kaze/ contains /z/. Rendaku is also blocked almost always when the second element of a compound is a recent loan into Japanese. Furthermore, rendaku may fail to occur even in contexts where no definite blocking factor is present.

In the Japanese writing system, rendaku affects how a morpheme is spelled when using one of the kana syllabaries: it causes the dakuten ("voicing mark", written as ゛) to be added to the upper right corner of the kana character that represents the first consonant and vowel in the second element of the compound. This is seen when comparing the hiragana spelling of kami (かみ) to that of origami (おりがみ). Rendaku is not marked in writing when a morpheme is spelled using kanji (logographs taken from Chinese characters). For example, kami (paper) is written with the kanji character 紙, which is unchanged when used in the spelling of origami (折り紙).

Linguistically, rendaku involves aspects of both pronunciation (phonology) and word structure (morphology), and so is categorized as a morphophonological phenomenon.