pronounced as /notice/Onbin (Japanese "euphony") is a set of sound changes that occurred in Early Middle Japanese around the end of the eighth century to the beginning of the tenth century, first attested in written texts of the Heian period. Onbin changes affected certain consonant-vowel sequences in non-word-initial position, causing them to become replaced with either a single vowel sound (as in Japanese: o'''i'''te, from earlier pronounced as //okite//) or a single consonant sound (as in Japanese: shi'''n'''de, from earlier pronounced as //sinite//). (In some cases, this also caused a change in the pronunciation of the preceding vowel or following consonant, as in the development of original pronounced as //te// to pronounced as //de// in Japanese: shi'''nd'''e.) Onbin played a role in diversifying the syllable structure of native Japanese words by creating heavy syllables that ended in two vowels or in a vowel followed by a consonant.
Historical onbin changes did not occur systematically, and some sequences could yield multiple outcomes. The non-deterministic nature of the historical sound changes is exemplified by doublets showing different outcomes of the same original form, such as Japanese: komichi (without onbin) versus Japanese: kōji (with u-onbin) from original pronounced as //komiti//, or Japanese: akindo (with N-onbin) versus Japanese: akyūdo (with u-onbin) from original pronounced as //akibito//. However, some onbin changes have come to be grammaticalized in the conjugation of Japanese verbs: as a result, certain verbs systematically display an "onbin stem" before certain suffixes in standard modern Japanese. The formation of these onbin stems varies between dialects.
The outcomes of onbin changes were bound moraic phonemes pronounced in the same syllable as the preceding vowel. Four distinct outcomes can be identified based on modern Japanese kana spellings: the two high vowels pronounced as //i u// and the two moraic consonants pronounced as //N Q//:
divides i-onbin and u-onbin into two categories based on whether they were originally nasalized, and so recognizes six possible outcomes of onbin in the Early Middle Japanese period: pronounced as //i u ĩ ũ N Q//.
The core set of onbin changes affected non-word-initial syllables that contained the consonants pronounced as //p k b ɡ m n// followed by pronounced as //i u//. (In this context, pronounced as //p// represents a consonant phoneme derived from Proto-Japonic *p: it was some kind of bilabial consonant in Early Middle Japanese, although its exact pronunciation is debated. The syllables transcribed here as pronounced as //pa pi pu pe po// are sometimes alternatively romanized as "fa fi fu fe fo" or "ha hi fu he ho": the use of "h" is anachronistic in terms of Early Middle Japanese pronunciation, but corresponds to the modern pronunciation of the kana that were used to spell these syllables in historical kana orthography, before Japanese script reform.) Some onbin changes could affect word-final syllables, such as the change of pronounced as //ki// to pronounced as //i// (as in pronounced as //kisaki// to pronounced as //kisai// 'empress') or pronounced as //ku// to pronounced as //u// (as in pronounced as //kaku// to pronounced as //kau// 'in this way'), and occasionally pronounced as //nu// to pronounced as //N//, or pronounced as //mi mu// to pronounced as //N// or pronounced as //ũ// (as in pronounced as //asomi// to pronounced as //asoN// 'courtier'). In contrast, onbin changes involving pronounced as //bi bu ɡi ɡu// seem to be attested only in the middle of words.
These core changes can be summarized as follows:
| Source | Outcome (modern hiragana/katakana) | Examples | ||||
|---|---|---|---|---|---|---|
| vowel | moraic consonant | source word | vowel | moraic consonant | ||
| pi pu | u (う/ウ) | Q (っ/ッ) | nipi₁ + ta taputo₁- | niuta tauto- | nitta tatto- | |
| ki | i (い/イ) | yoki₁ | yoi | |||
| ku | u (う/ウ) | takume₂ | taume | |||
| bi | ũ > u (う/ウ) | N (ん/ン) | aki₁ + bi₁to₂ | akiũdo | akindo | |
| bu | ũ > u (う/ウ) |
| saũzaũ-(si)- | |||
| gi | ĩ > i (い/イ) | tugi₁te | tuĩde | |||
| gu | ũ > u (う/ウ) | N (ん/ン) | kagupasi | kaũbasi | kanbasi | |
| mi mu | ũ > u (う/ウ) | N (ん/ン) | ko₁ + mi₁ti pi₁ + muka(si) | koũdi piũga | kondi pingasi | |
| ni nu | N (ん/ン) | sinite kinu + kaki | sinde kingai | |||
Subscript numbers distinguish syllables that were different in Old Japanese, as indicated by man'yōgana, but that merged in the transition to Early Middle Japanese. considers it likely that onbin changes affected only pronounced as //pi₁ ki₁ mi₁ bi₁ gi₁// and not pronounced as //pi₂ ki₂ mi₂ bi₂ gi₂// (and so took place before their merger), whereas disagrees. Since syllables with /i₂/ were less frequent, the relevant evidence is limited, and there is a possible case of pronounced as //ki₂// > pronounced as //i// in the word, normally derived from Old Japanese tuki₂ "moon, month": Frellesvig argues this could be a folk etymology.
When the consonant in the affected sequence was either nasal pronounced as //m n// or prenasalized pronounced as //b g//, onbin produced a nasal output: either a nasalized high vowel pronounced as //ĩ, ũ// or a moraic nasal consonant pronounced as //N//. These nasal sounds caused following pronounced as //p t k s// to be replaced with their prenasalized counterparts, pronounced as //b d g z//. By Late Middle Japanese, the nasalized vowels pronounced as //ĩ, ũ// had merged with pronounced as //i, u//, and the change of pronounced as //p t k s// to pronounced as //b d g z// after a nasal sound ceased to apply as an automatic process, although it had lasting effects on the form of some inflectional morphemes and lexicalized compound words.
During Late Middle Japanese, vowel sequences ending in pronounced as //u// (including that derived from earlier pronounced as //ũ//) fused into long vowels (which can be phonologically analyzed as sequences of two identical vowel phonemes in one syllable). If the first vowel was originally pronounced as //i// or pronounced as //e//, the resulting long vowel was preceded by a palatal glide pronounced as //j//. This produced the following outcomes:
| pronounced as //iu// | pronounced as //juu// | pronounced as //juu// | |
| pronounced as //eu// | pronounced as //joo// | pronounced as //joo// | |
| pronounced as //au// | pronounced as //ɔɔ// | pronounced as //oo// | |
| pronounced as //ou// | pronounced as //oo// | pronounced as //oo// |
Because of this vowel fusion, words with u-onbin, such as, do not always contain the vowel phoneme pronounced as //u// in modern Japanese, although they are still spelled with the kana う/ウ (u) because of a convention of spelling long pronounced as /[oː]/ non-phonetically in this context.
As a result of onbin changes, consonant-stem verbs developed variant "onbin stems" used before certain suffixes (in modern Japanese, the past Japanese: -ta, gerund Japanese: -te, conditional Japanese: -tara, and representative Japanese: -tari). Consonant-stem verbs are those that can be analyzed as having underlying stems that end in a consonant (in modern Japanese, any of pronounced as //w t k b ɡ m n r s//): these verbs take the suffix Japanese: -u in the dictionary form, in contrast to vowel-stem verbs, which have stems that end in either pronounced as //e// or pronounced as //i// and take the suffix Japanese: -ru in the dictionary form. In Japanese grammatical terminology, consonant-stem verbs are called verbs, because their inflected forms make use of the five kana that represent the stem-final consonant plus each of the five Japanese vowels (pronounced as //a i u e o//). Verbs with stems ending in pronounced as //w// show an additional complication: stem-final pronounced as //w// is deleted before suffixes that start with pronounced as //i u e o//, since Japanese phonotactics only allow pronounced as //w// to occur before the vowel pronounced as //a//. In terms of historical development, verb stems that end in pronounced as //w// originally ended in the consonant *p.
The onbin stem developed from the Early Middle Japanese infinitive (Japanese: ren'yōkei) form, which ended in pronounced as //i//. When the infinitive form of a consonant-stem verb ended in one of the syllables pronounced as //pi ki bi ɡi mi ni//, it could undergo the onbin sound changes described above. In addition, it came to be possible for pronounced as //ri ti si// to undergo analogous changes in this context: thus, pronounced as //ri ti// could become pronounced as //Q// (as in pronounced as //torite// > pronounced as //toQte//, pronounced as //motite// > pronounced as //moQte//) and pronounced as //si// could become pronounced as //i// (as in pronounced as //idasite// > pronounced as //idaite//). argues that verbs with stems ending in pronounced as //r t s// developed onbin stems purely as a result of the morphological process of analogy, rather than as a result of the same phonetic processes as the other onbin changes.
In modern Standard Japanese, the form of a verb's onbin stem can typically be predicted from the underlying stem-final consonant: pronounced as //w r t// give pronounced as //Q//, pronounced as //b m n// give pronounced as //N// (with voicing of the following pronounced as //t// to pronounced as //d// in the suffix), pronounced as //k// gives pronounced as //i//, and pronounced as //ɡ// gives pronounced as //i// (with voicing of the following pronounced as //t// to pronounced as //d// in the suffix). Verbs with underlying stems ending in pronounced as //s// do not show onbin in contemporary standard speech, but instead use pronounced as //si// (Japanese: -shi-) before the relevant suffixes.
| stem consonant | onbin type | Example verb forms | |||
|---|---|---|---|---|---|
| Dictionary | Negative | Gerundive | |||
| pronounced as //w// (original p) | pronounced as //Q// Japanese: -t-t- | Japanese: morau | Japanese: moraw-anai | Japanese: morat-te | |
| pronounced as //r// | Japanese: hasiru | Japanese: hasir-anai | Japanese: hasit-te | ||
| pronounced as //t// | Japanese: motsu | Japanese: mot-anai | Japanese: mot-te | ||
| pronounced as //b// | pronounced as //N// Japanese: -n-d- | Japanese: asobu | Japanese: asob-anai | Japanese: ason-de | |
| pronounced as //m// | Japanese: nomu | Japanese: nom-anai | Japanese: non-de | ||
| pronounced as //n// | Japanese: shinu | Japanese: shin-anai | Japanese: shin-de | ||
| pronounced as //k// | pronounced as //i// Japanese: -i-t- | Japanese: kaku | Japanese: kak-anai | Japanese: kai-te | |
| pronounced as //ɡ// | pronounced as //i// Japanese: -i-d- | Japanese: oyogu | Japanese: oyog-anai | Japanese: oyoi-de | |
is the only n-stem verb in modern Japanese.
A few verbs have an exceptionally formed onbin stem. For example:
Dialects show some differences in the formation of onbin stems. Some dialects regularly use u-onbin (with fusion of pronounced as //iu eu au ou// to pronounced as //juu joo oo oo//) for verb with underlying stems that end in pronounced as //w// (where standard Japanese has Q-onbin) or verbs with underlying stems that end in pronounced as //m b// (where standard Japanese has N-onbin).
The use of onbin stems in inflected verb forms never become normative in literary written Classical Japanese. It is difficult to tell how frequent they were in speech at various historical periods.
, citing, gives the following chronology for the written attestation of onbin in verb forms:
However, suggests that onbin changes must have been active well before these dates, arguing that they precede the intervocalic merger of pronounced as //p// and pronounced as //w// (dated at the latest to the end of the 10th century) and most likely began in the early 9th century or even the late 8th century.
Two suffixes used in the inflection of adjectives underwent onbin changes. The Old Japanese adnominal ending -ki developed by onbin into the Late Middle Japanese and Modern Japanese nonpast ending Japanese: -i, as in Japanese: takai, the nonpast form of the adjective stem . The adjectival infinitive ending -ku developed an onbin variant Japanese: -u: however, Japanese: -ku remains the normal form of this ending in Standard Japanese. The use of Japanese: -u (which fuses with the preceding vowel) as an adjectival infinitive ending is a characteristic of the language spoken in the Kansai (including Kyoto) and Kyushu regions. Using the adjective Japanese: taka- again as an example, the Kansai dialect form Japanese: takō corresponds to the Standard Japanese infinitive Japanese: takaku. The pronunciation of the adjectival infinitive ending as Japanese: -u in Kyoto vs. Japanese: -ku in the Kanto region is mentioned as a dialectal difference in Rodrigues' Arte da Lingoa de Iapam. The variant ending Japanese: -u shows some limited use in Standard Japanese as part of the rarely used "super-polite" construction (which occurs when the adjective is followed by the copula Japanese: gozaimasu) and in a few isolated, fixed expressions: its use in these contexts can be attributed to borrowing from the Kyoto dialect.
Onbin sound changes likely had their roots in earlier phonetic variation in the pronunciation of Old Japanese consonants and vowels. Namely, the Old Japanese consonants pronounced as //p k// might have varied phonetically between voiceless stops pronounced as /[p k]/, voiced stops pronounced as /[b g]/, voiceless fricatives pronounced as /[ɸ x]/, and voiced continuants pronounced as /[β ɣ]/. The consonants pronounced as //b g// were prenasalized and possibly could vary between stops pronounced as /[ᵐb ᵑg]/ and continuants pronounced as /[ᵐβ ᵑɣ]/; vowels before pronounced as //b g m n// were likely phonetically nasalized. The high vowels pronounced as //i u// could possibly be reduced to coarticulations [ʲ ʷ] on the preceding consonant.
Between vowels in the middle of a word, original pronounced as //p// merged with the phoneme pronounced as //w// around the second half of the tenth century or during the 11th century. After this merger, pronounced as //w// eventually was lost before any vowel other than pronounced as //a//. At the start of a word, original pronounced as //p// had come to be regularly pronounced as a voiceless labial fricative pronounced as /[ɸ]/ by the end of the 16th century (later on, a 17-18th century sound change turned pronounced as /[ɸ]/ into pronounced as /[h]/ before any vowel other than pronounced as //u//). It was once widely thought that pronounced as //p// was completely replaced with pronounced as /[ɸ]/ already in Old Japanese, but argues that this assumption is not well justified. According to the traditional assumption, intervocalic pronounced as //p// merged with pronounced as //w// as a result of pronounced as /[ɸ]/ being voiced to pronounced as /[w]/. According to a competing hypothesis, word-medial intervocalic pronounced as //p// was already phonetically voiced pronounced as /[b]/ or pronounced as /[β]/ in Early Middle Japanese prior to its merger with pronounced as /[w]/.
Consonantal variants of verbal onbin stems are attested later than the vocalic variants, but this does not necessarily mean that consonantal onbin are chronologically more recent sound changes: it could simply mean that the varieties of speech in which they arose were not well represented in writing until later on.
There is disagreement about the exact phonetic path by which onbin developed. The development of the consonantal onbin N and Q can be explained in terms of vowel deletion, whereas the development of i- and u-onbin can be interpreted as involving deletion of consonants between vowels. If intervocalic consonant deletion is the correct explanation for the origin of u-onbin from sequences involving original labial consonants (pronounced as //p b m//), then the deletion of these consonants must have been preceded by a sound change that turned pronounced as //pi bi mi// into pronounced as //pu bu mu// in contexts where onbin would occur. Such a change does appear to be attested by spelling variations in texts from the 11th and 12th centuries, although some of this evidence admits other interpretations (such as a change of pronounced as //bi mi// in this context to a moraic pronounced as /[m]/ sound). The hypothesis of intervocalic consonant deletion implies that in cases where i-onbin or u-onbin is derived from a consonant-vowel sequence that originally started with a nasal or prenasalized consonant, the change of following pronounced as //p t k s// to prenasalized (modern voiced) pronounced as //b d g z// was not caused by assimilation between adjacent consonants; rather, it may have arisen by 'rightward' (progressive) spreading of nasality from a phonetically nasalized vowel that originally preceded the deleted consonant. The following examples illustrate ways i- and u-onbin might have developed per this approach:
De Chene 1991 advocates an alternative account for the development of i-onbin from original pronounced as //gi// and u-onbin from original pronounced as //mu mi bu bi gu//, arguing there was an initial change of pronounced as //gi// to moraic pronounced as /[ɲ]/, pronounced as //gu// to moraic pronounced as /[ŋ]/, and pronounced as //mu mi bu bi// to moraic pronounced as /[m]/, followed by vocalization of moraic pronounced as /[ɲ]/ to pronounced as /[i]/ and of moraic pronounced as /[ŋ]/ and pronounced as /[m]/ to pronounced as /[u]/ (in cases where they did not alternatively become pronounced as //N//). In support, de Chene cites the development of pronounced as /[u]/ from original pronounced as //ga// in the form kauburu "to place on the head' from kagapuru, arguing that this is easier to explain in terms of moraic nasal formation and vocalization (pronounced as /[ᵑga]/ > pronounced as /[ŋ]/ > pronounced as /[u]/) rather than intervocalic consonant loss. De Chene also argues that the lack of onbin outcomes for word-final pronounced as //gi// and pronounced as //bu bi gu// implies that the development of these sequences to pronounced as //i// and pronounced as //u// involved a different mechanism from the intervocalic consonant deletion seen in the development of pronounced as //ki ku// to pronounced as //i u//, which could occur word-finally. Like de Chene, considers it possible that pronounced as //gi// became pronounced as //i// by means of vocalization of pronounced as /[ɲ]/, as in pronounced as /[kõᵑgʲite] > [kõɲde] > [kõĩde]/. De Chene interprets the use in Heian-era texts of the "mu" kana in the spelling of words like "yomutaru" as an orthographic device representing moraic pronounced as //m//; the following examples illustrate the development of u-onbin according to this approach:
Instead of vowel or consonant deletion, prefers to explain onbin as a consequence of phonetic reduction of both the consonant and vowel, resulting in their fusion into a single phonetic segment (e.g. pronounced as //mi/ > [mʲː], /pi/ > [βʲː]/): that could then be phonologically reinterpreted as a single phoneme (vocalic or consonantal). The following example illustrates Frellesvig's approach to explaining onbin:
The onbin sound changes discussed above turned consonant-vowel sequences (such as pronounced as //bi ɡi mi ni// or pronounced as //bu ɡu mu nu//) into single segments (such as pronounced as //ĩ ũ N//) that still counted as a mora when measuring the length of a word. However, some words appear to show a similar but distinct outcome, where a sequence such as pronounced as //mi// or pronounced as //ni// was reduced to prenasalization of the following consonant without leaving a moraic phoneme behind. These outcomes might be the result of sporadic reductions that were similar to onbin changes but occurred earlier, during time periods when syllables were only permitted to end in a short vowel. Reduction of the genitive particle no or the dative particle ni may be the origin of rendaku, or voicing of the second element of a Japanese compound word, which occurs often but not automatically.
Examples:
The words listed below show the effects of onbin as a sound change, not including the grammatical onbin seen in verb and adjective forms. Many examples are compound words, in which case the first consonant of the second element may or may not become voiced as a result of rendaku. In some cases, it is not possible to determine whether rendaku was present before the application of onbin sound changes.
The Old Japanese morpheme pi₁to₂ 'person' (Modern Japanese ; with rendaku) often shows u-onbin as the second element of a compound, producing words ending in or, or with rendaku, or . Examples include:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes |
|---|---|---|---|---|
| pi | siro-pi₁to₂ 'white-person' | sirouto | shiroto, shirabito | |
| kuro-pi₁to₂ 'black-person' | kurouto | kuroto | ||
| oto₂ + pi₁to₂ 'younger sibling' + 'person' | otouto | |||
| imo₁ + pi₁to₂ 'sister' + 'person' | imouto | |||
| si + pi₁to₂ | siuto | |||
| bi | aki₁ + pi₁to₂ > aki-bi₁to₂ 'trade-person' | akiũdo | akindo | |
| kari + pi₁to₂ > kari-bi₁to₂ 'hunt' + 'person' | kariudo | |||
| kura + pi₁to₂ > kura-bi₁to₂ 'warehouse' + 'person' | kuraudo | kurabito, kurando, kuraudu | ||
| naka + pi₁to₂ > naka-bi₁to₂ 'middle/inside/relationship' + 'person' | nakaudo |
Other examples from core sources (as per Frellesvig's categorization), excluding morphological onbin in verb and adjective inflection:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes |
|---|---|---|---|---|
| pu | tapu-to₁- | tauto- | tatto- | |
| ku | takume 'wholly' | taume | ||
| bu |
| saũzaũ-(si)- | ||
| gu | ka + -kupasi > ka-gupasi | kaũbasi | kanbasi | |
| wara + kutu > wara-gutu 'straw'+'footwear' | waraũdu | (obsolete) | warazu, waranzu, waraji, waranji | |
| sita + kutu > sita-gutu 'below, under'+'footwear' | sitaũdu | sitagutu | ||
| mi | ko₁-mi₁ti 'small+road' | koũdi | kondi | |
| te-mi₁du 'hand+water' | teũdu | temizu | ||
| kami₁-so 'paper+hemp' | kaũzo | |||
| kami₁-tu-ke₂no₁ 'high/upper Keno' | kaũduke(no) | (place name) | ||
| kami₁-pe₁ (or kami₁-be₁) 'upper+side' | kaũbe | |||
| kami₂-gami₂(si) | koũgoũ(si) | |||
| mu | pi₁-muka(si) | piũga | (place name) | pingasi |
| kamu-pe₁ (or kamu-be₁) 'god-house' | kaũbe | (place name) |
| wi > u | mawide | maude | ||
| wo > u | mawos- | maus- | ||
| ga > ũ | kagapuri | kaũburi | kaburi, kamuri, kanburi, kanmuri | |
| kagapuru | kaũburu | kaburu, kamuru | ||
| pa > u | papaki₁ | pauki | ||
| kapabori? | kaubori/-mori | kawahori |
Examples from core sources (as per Frellesvig's categorization), excluding morphological onbin in verb and adjective inflection:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes |
|---|---|---|---|---|
| ki | yaki₁ + pa > yaki-ba 'burned-edge' | yaiba | ||
| tuki₁ + kaki₁ | tuigaki | (archaic) | ||
| tuki₁ + fidi | tuizi | |||
| suki + kaki₁ | suigai | (archaic) | suigaki | |
| saki₁-tama | saitama | (place name) | Saidama | |
| gi | tugi₁te | tuĩde | ||
| tugi-matu | tuimatu | (archaic) |
Examples from core sources (as per Frellesvig's categorization), excluding morphological onbin in verb and adjective inflection:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes |
|---|---|---|---|---|
| ni | nani | naN | ||
| nu | kinu + kaki 'silk'+'fence'[1] | kiNgai | (archaic) | |
| mi | womi₁na | woNna | wouna (archaic) | |
| mu | kamukapu | kaNgapu | ||
| kamu-nagi kamu-nusi | kaNnagi kaNnusi | kaunagi | ||
| bi | aki₁ + pi₁to₂ > aki-bi₁to₂ 'trade-man' | akiNdo | akiudo > akyūdo | |
| gu | ka + -kupasi > ka-gupasi | kaNbasi | kaũbasi | |
| wara + kutu > wara-gutu 'straw' + 'footwear' | waraNdu | (obsolete) | warazu, waraji, waraudu > warōzu |
From other sequences:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes | |
|---|---|---|---|---|---|
| di > N | kadi + tori 'rudder/oar' + 'take' | kaNdori | |||
| ga > N | kagapuri | kaNburi | kōburi, kaburi, kamuri | ||
| ma > N | sama | saN | (polite suffix) | ||
| mo > N | nemoko₂ro₂ | neNgoro |
Examples from core sources (as per Frellesvig's categorization), excluding morphological onbin in verb and adjective inflection:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes | |
|---|---|---|---|---|---|
| pi |
| nitta | (a surname) | niuta | |
| wotto | ||||
| pu | tapu-to₁- | tatto- | tauto- |
From other sequences:
| source | Old Japanese | outcome | Modern Japanese | alternative outcomes | |
|---|---|---|---|---|---|
| ri |
| katta | (place name) | ||
| pori-su | possu | ||||
| kusuguri-ta- | kusugutta- | ||||
| ru | urutapu | uttapu | |||
| ti |
| moppara | |||
| utte | ||||
| tu |
| yakko | |||
| ra | warapa | wappa | (archaic) | warawa |