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.

Rendaku is common in Japanese, but does not occur in all compound words. A rule known as Lyman's law prevents rendaku if the second element of a compound word already contains one or more of the voiced obstruent consonant phonemes /d ɡ z b/. For instance, the morpheme kaze (wind) contains the voiced obstruent consonant /z/, and so its first consonant /k/ remains voiceless and unaffected by rendaku in the compound word umikaze (sea breeze).^[1] Rendaku is also systematically blocked if the second element of a compound is a recent loanword into Japanese from a foreign language. 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, since rendaku involves aspects of both pronunciation (phonology) and word structure (morphology), it is categorized as a morphophonological phenomenon.