Rendaku (, Japanese pronunciation: [?endak?], lit. "sequential voicing") is a phenomenon in Japanesemorphophonology that governs the voicing of the initial consonant of the non-initial portion of a compound or prefixed word. In modern Japanese, rendaku is common but at times unpredictable, with certain words unaffected by it.
While kanji do not indicate rendaku, they are marked in kana with dakuten (voicing mark).
In some cases, rendaku varies depending on syntax. For instance, the suffix t?ri (, "road, following"), from t?ru (, "to go, to follow"), is pronounced as -t?ri (?) following the perfective verb, as in omotta-t?ri (, "as I thought"), but is pronounced as -d?ri (?, with rendaku) when following a noun, as in yotei-d?ri (?, "as planned, according to schedule") or, semantically differently - more concretely - Muromachi-d?ri (, "Muromachi Street").
Rendaku occurs not only on single-root morphemes, but also "multi-root" morphemes, those that are themselves composed of smaller morphemes. These morphemes may also be of Chinese origin (see kango) or even of non-Literary-Chinese origin (see gairaigo) rather than strictly native.
Here, kappa is a Portuguese-origin gairaigo, from the Portuguese word capa ("cloak; cape")
Notice that for certain morphemes that begin with the morae chi (?) and tsu (?), their rendaku forms begin with the morae ji and zu, spelled precisely in hiragana as ? and ?, which explains the use of these kana in contrast to the identically pronounced ? and ? (see yotsugana). This isn't a hard and fast rule, however, because it's relaxed in certain older compounds or names, especially those that are so consolidated that they could hardly be recognized as compounds anymore, but rather, as single words themselves.
Rendaku occurs not only in compound nouns, but also in compounds with adjectives, verbs or continuative/nominal forms of verbs.
Research into defining the range of situations affected by rendaku has largely been limited to finding circumstances (outlined below) which cause the phenomenon not to manifest.
Lyman's Law states that there can be no more than one voiced obstruent (a consonant sound formed by obstructing airflow) within a morpheme. Therefore, no rendaku can occur if the second element contains a voiced obstruent. This is considered to be one of the most fundamental of the rules governing rendaku.
yama + kado > Yamakado, not *Yamagado ("mountain" + "gate" > place name) (* indicates a non-existent form)
hitori + tabi > hitoritabi, not *hitoridabi ("one person" + "travel" > "traveling alone")
Despite a number of rules which have been formulated to help explain the distribution of the effect of rendaku, there still remain many examples of words in which rendaku manifests in ways currently unpredictable. Some instances are linked with a lexical property as noted above but others may obey laws yet to be discovered. Rendaku thus remains partially unpredictable, sometimes presenting a problem even to native speakers, particularly in Japanese names, where rendaku occurs or fails to occur often without obvious cause. In many cases, an identically written name may either have or not have rendaku, depending on the person. For example, may be read in a number of ways, including both Nakata and Nakada.
Voicing of preceding consonant
In some cases, voicing of preceding consonants also occurs, as in sazanami (, ripple), which was formerly sasa-nami. This is rare and irregular, however.
^Otsu, Yukio (1980). "Some aspects of rendaku in Japanese and related problems". MIT Working Papers in Linguistics: Theoretical Issues in Japanese Linguistics 2: 207-227.
End?, Kunimoto (1981). "Hirendaku no H?zoku no Sh?ch? to Sono Imi: Dakushion to Bion to no Kankei kara". Cite journal requires |journal= (help) (Japanese citation: ?(1981)--?(50-3))
Irwin, Mark (April 2005). "Rendaku-based Lexical Hierarchies in Japanese: The Behaviour of Sino-Japanese Mononoms in Hybrid Noun Compounds". Journal of East Asian Linguistics. 14 (2): 121-153. doi:10.1007/s10831-004-6306-9. ISSN0925-8558.