Japanese conjugation

Derivative verb bases

There are three modern verb base forms that are considered to be derived from older forms. These are the potential, hortative, and euphonic sub‑bases, as shown in the Verb base formation table above.

As with all languages, the Japanese language has evolved to fulfil the contemporary needs of communication. The potential form of verbs is one such example. In Old Japanese and Early Middle Japanese, potential was expressed with the verb ending yu (ゆ), which was also used to express the passive voice ("to be done") and the spontaneous voice ("something happens on its own"). This evolved into the modern passive ending -(ra)reru (（ら）れる), which can similarly express potential and spontaneous senses. As usage patterns changed over time, different kinds of potential constructions emerged, such as the grammatical pattern of the rentaikei base + -koto ga dekiru (〜ことができる), and also via the kanōkei base. The historical development of the kanōkei base is disputed, however the consensus is that it stemmed from a shift wherein transitive verbs developed an intransitive sense similar to the spontaneous, passive, and potential, and these intransitive forms conjugated in the 下二段活用 (shimo nidan katsuyō, lower bigrade conjugation pattern) of the Classical Japanese of the time. The lower bigrade conjugation pattern evolved into the modern ichidan pattern in modern Japanese, and these stems for godan verbs have the same form as the hypothetical stems in the table above.

The mizenkei base that ends with -a was also used to express the hortative mood for yodan verbs (四段動詞, yodan-dōshi; "Class‑4 verbs") in Old Japanese and Middle Japanese,^{[disambiguation needed]} in combination with hortative suffix -mu (む). Sound changes caused the resulting ‑amu ending to change: /‑amu/ → /‑ãu/ → /‑au/ (like English "ow") → /‑ɔː/ (like English "aw") → /‑oː/. The post‑WWII spelling reforms updated spellings to reflect this and other sound changes, resulting in the addition of the ishikei or hortative base, ending with -o, for the hortative mood of yodan verbs. This also resulted in a reclassification of "yodan verbs" to "godan verbs" (五段動詞, godan-dōshi; "Class‑5 verbs").

The ren'yōkei base also underwent various euphonic changes specific to the perfective and infinitive (te) forms for certain verb stems, giving rise to the onbinkei or euphonic base. In the onbinkei base, the inflectional suffixes for godan verbs vary according to the last kana of the verb's ren'yōkei base.

The bases of suru

Unlike most verbs, suru (する) and its derived compounds exhibit strong irregularity in their verb bases. In some cases, some variants are preferred over the others, and such preferences vary among speakers. Roughly speaking, there are three major groups that behave similarly:

• Group A: Suru itself and compounds of it and free nouns (which are usually, but not always, spelt with two more kanji if Sino-Japanese): jikkō suru (実行する; 'practise'), toku suru (得する; 'gain'), son suru (損する; 'lose'), bikkuri suru (吃驚する; 'be startled'), janpu suru (ジャンプする; 'jump'), etc.
• Group B: Compounds with bound Sino-Japanese morphemes that behave more like godan verbs. These often have full-fledged, interchangeable godan derivatives: aisu(ru) (愛す(る); 'love'), zokusu(ru) (属す(る); 'belong'), tassu(ru) (達す(る); 'reach'), etc.

  Such a form as aisenu (愛せぬ) is supposed to be the classical Japanese equivalent to aisanai (愛さない). Compare the following translations of 1 John 3:14 ("[…] Anyone who does not love remains in death."):

  1917 classical: […] aisenu mono wa shi no uchi ni oru. ([…]愛せぬ者は死のうちに居る。)

  1955 modern: […] Aisanai mono wa, shi no uchi ni todomatte iru. ([…]愛さない者は、死のうちにとどまっている。)

  However, aisenu ("not love") as the negative of aisu(ru) ("love") would likely be confused with aisenu ("cannot love") as the negative of the potential aiseru ("can love") in modern Japanese. It is clear that aisenu is not the same as aisanu where they both occur in close proximity: Wa ga ko o aisanu mono wa arimasen. Wa ga ko sae aisenu mono ga, dō shite goshukun o aisemashō. (わが子を愛さぬ者はありません。わが子さえ愛せぬ者が、どうしてご主君を愛せましょう。; transl. No man does not love his own son. If he is not capable of loving even his own son, in what way could he ever love his lord?).

  There is great variety among Group-B verbs as to whether to choose between the godan-negative ‑san(u)/‑zu and the classical-negative ‑sen(u)/‑zu, and there are indeed cases where only contexts can clarify whether ‑sen(u)/‑zu are truly classical-negative, or actually godan-negative-potential. In general, it seems that if the Sino-Japanese stem contains a moraic obstruent as in kussuru (屈する; くっする, /kɯQsɯɾɯ/), a moraic nasal as in hansuru (反する; はんする, /haNsuru/), or lengthening mora as in kyōsuru (供する; きょうする, /kjoRsɯɾɯ/), the godan options are less preferable with all auxiliaries (including the negative ‑n(u)/‑zu), though not impossible. Thus, such forms as kussenu/kussezu (屈せぬ・屈せず; 'not bend') are more likely to be classical-negative, while such forms as aisenu/aisezu (愛せぬ・愛せず; 'cannot love') are more likely to be godan-negative-potential; and while both kussanu/kussazu (屈さぬ・屈さず; 'not bend') and aisanu/aisazu (愛さぬ・愛さず; 'not love') are unambiguously godan-negative, the former are not as likely as the latter.

• Group C: Compounds with bound Sino-Japanese morphemes that behave more like upper (i-stemmed) ichidan verbs. These often have full-fledged, interchangeable upper ichidan derivatives: ronzuru → ronjiru (論ずる→論じる; 'discuss'), ōzuru → ōjiru (応ずる→応じる; 'respond'), omonzuru → omonjiru (重んずる→重んじる; 'appreciate'), sassuru → sasshiru (察する→察しる; 'surmise'), etc.
• Group D: Compounds with bound Sino-Japanese morphemes that behave more like lower (e-stemmed) ichidan verbs. These may have full-fledged, interchangeable lower ichidan derivatives: shinzuru → shinzeru (進ずる→進ぜる; 'provide') and misuru → miseru (魅する→魅せる; 'enchant').

Across the following forms of suru within standard Japanese, an eastern dialect, while there is a dominance of the eastern vowel i as in shinai, shiyō and shiro, the once prestigious western vowel e, as in sen(u) and seyo, still has currency especially in formal or literary Japanese. Such variants as senai and sanai (both of shinai); shin(u) (of sen(u)); shō (← seu), seyō and sō (all of shiyō); sero (of shiro); and shiyo, sē and sei (all of seyo), remain dialectal or obsolete.

Copulae: Conjugation table

The copulae of Japanese demonstrate suppletion, in that they combined different forms from different words into one word. The original copulae were all based on the verb ari (あり; 'to exist'), which evolved into the modern aru (ある). It needed to be preceded by one of the three particles, ni, nite → de and to, which yielded three variants, ni ari/ni aru → nari/naru, de ari/de aru → da and to ari/to aru → tari/taru, the last of which fell out of use, but did phonetically coincide with te ari/te aru → tari/taru, which in turn evolved into the modern past auxiliary ta. It also combined with adjectival roots to expand their conjugation, for example akaku arō → akakarō (赤かろう), akaku atta → akakatta (赤かった), etc.

• The original conclusive de ari, was replaced by the attributive de aru, which evolved into the informal conclusive da, and the formal conclusive de aru. In terms of formality and politeness:
  • Da is informal and impolite. Depending on specifically what precedes it, da can be perceived as abrupt or too masculine, and therefore is customarily omitted in some cases.
  • De aru is formal and nonpolite (with no inherent assumption of politeness).
  • Desu is nonformal (with no inherent assumption of formality) and polite.
  • De arimasu is formal and polite.
• Da/datta/darō are the colloquial contractions of de aru/de atta/de arō in eastern dialects (including Tokyo Japanese). Their western equivalents include ja/jatta/jarō and ya/yatta/yarō. Ja/jatta/jarō, along with other western features (‑n(u), ‑nanda, u‑onbin, etc), are occasionally used in faux-archaic speech or old people's speech rather dialectal speech; for example, the character Gandalf, an ancient wizard from The Lord of the Rings, is made to speak with a few selectively chosen western features, while still retaining some eastern features, in the Japanese translations (see relevant quotations in the footnotes).
• Gozaru (御座る; contracted from goza aru) is the honorific version of aru, and goza(r)imasu is the honorific version of arimasu. Gozaru has most of the forms that aru does ((de (wa)) gozaru, (de (wa)) gozaranu, (de (wa)) gozareba, etc), although it additionally undergoes a minor sound change in the polite conclusive/attributive gozarimasu → gozaimasu and the imperative gozare → gozai. Gozaimasu is authentically used in modern Japanese, while gozaru, gozarimasu(ru) and gozaimasuru are used for effect, such as in theatrical or humorous lines.
• The current attributive form of de (wa) aru is still de (wa) aru. Da additionally takes naru → na (of said nari) as its attributive form only in adjectival verbs, as in kirei na hana (綺麗な花; 'pretty flower', lit. 'a flower, which is pretty'), and after the auxiliaries sō (そう), yō (よう) and mitai (みたい), as in rikō sō na kao (利口そうな顔; 'smart-looking face', lit. 'a face, which appears smart') and kanojo no yō na hito (彼女のような人; 'someone like her', lit. 'a person, who is like her'); while the particle no is used after nouns, as in tomodachi no Yūko (友達の裕子; 'my friend Yūko', lit. 'Yūko, who is my friend') or bijin no onēsan (美人のお姉さん; 'my beautiful sister', lit. 'my sister, who is a beauty'). However, since no also expresses possession, this may cause ambiguity, as in isha no ojisan (医者のおじさん; lit. 'my uncle, who is a doctor; my doctor's uncle'); moreover, some nouns can function as either "adjectival verbs" or "nouns", and take either na or no, such as iroiro na mono/iroiro no mono (色々な物・色々の物; 'various things'). The old naru (of said nari) and taru (of said to ari/to aru → tari/taru) can still be used for literary effect, as in zetsudai naru gokitai (絶大なるご期待; 'the utmost anticipation'), Hokkaidō naru chihō (北海道なる地方; 'Hokkaido region'), isha taru hito (医者たる人; 'a person, who is known as a doctor'), kyōshi taru mono (教師たるもの; 'those who call themselves teachers'), or in such idiom as sei naru (聖なる; 'holy') or dōdō taru (堂々たる; 'splendid'). Incidentally, an ancient possessive na was fossilized in words like manako (眼; 'eyeball', lit. 'eye's child'), minato (港; 'harbor', lit. 'water's door'), tanagokoro (掌; 'palm', lit. 'hand's heart'), etc. There is also a niche distinction between Kōbe no hito (神戸の人; 'person from Kobe', lit. 'Kobe's person') and Kōbe na hito (神戸な人; 'person seeming like they could be from Kobe', lit. 'Kobe-ish person'). Na is also used before the nominalizer no, as in sobo wa hyakusai na no da (祖母は100歳なのだ; lit. 'it's a fact that my grandma is 100 years old').
• De is morphologically a gerund, for it is constructed by combining its infinitive (ni) with the gerundive particle ‑te as with any other gerund. In modern Japanese, it itself functions as both an infinitive and a gerund. When combining with aru to create finite forms, it is de that is used, not ni which is classical and merely fossilized in the attributive na(ru) (← ni aru) and the provisional nara(ba) (← ni araba). Another gerund, de atte is occasionally found in writing: Yonin wa izure mo hitonami ijō ni tsuyoi jiga no mochinushi de atte, kesshite dakyō nado shinai (四人はいずれも人並み以上に強い自我の持ち主であって、決して妥協などしない; 'Each of the four is the possessor of a stronger ego than the average man and never makes compromises').
• De and de ari are the more common infinitives: Shika shi karera wa sugureta bunka de ari goraku de aru eiga o hitori de mo ōku no hito ni misetai to doryoku shite kita dake de aru (しかし彼らは優れた文化であり娯楽である映画を一人でも多くの人に見せたいと努力してきただけである; 'But they have only endeavored to show to as many people as possible films that are outstanding culture and are entertainment'). It is rare to find ni used alone with an ordinary noun: Sore ga munensa ni wakayome wa sato e kaetta kiri modotte konai (それが無念さに若嫁は里へ帰ったきり戻ってこない; 'With that as a resentment, the bride returned to her village and would not return'); ni meaning "as," however, can be treated as an infinitive: Uchi wa okyakusama ni gaijin no kata ga ōi n de, asuparagasu, burokkorī nado no seiyō yasai ga yoku demasu (うちはお客様に外人の方が多いんで、アスパラガス、ブロッコリーなどの西洋野菜がよく出ます; 'As customers we have mostly foreigners, so lots of foreign vegetables like asparagus and broccoli are out for sale'). Other types of nouns, such as adjectival nouns (heiwa ni (平和に; 'peacefully; in a peaceful way')), auxiliary nouns (yō ni (ように; 'in a way like')), demonstrative pronouns (koko ni (ここに; 'here')) etc, can be readily paired with ni when used adverbially.
• The infinitives combine with different words, each with its own parallel:
  • de + aru → de aru ("be"), parallel with akaku + aru → akaku aru ("be red") and nomi + suru → nomi suru ("drink")
  • de + nai → de nai ("not be"), parallel with akaku + nai → akaku nai ("not be red") and nomi + shinai → nomi shinai ("not drink")
  • de ari + ‑masu → de arimasu ("be"), parallel with nomi + ‑masu → nomimasu ("drink")
• The above formations allow "splitting", or adding particles like wa or mo between the infinitive forms and the following verbs, which would be impossible with da ("be"), akai ("be red") and nomu ("drink") alone:
  • da ("be"), parallel with akai ("be red") and nomu ("drink")
  • de wa aru ("be …, indeed"), parallel with akaku wa aru ("be red, indeed") and nomi wa suru ("drink, indeed")
  • de wa nai ("not be …, indeed"), parallel with akaku wa nai ("not be red, indeed") and nomi wa shinai ("not drink, indeed")
• The particles wa and mo are often added, especially to the negatives, although not required in principle. Wa puts focus on what goes after it, while mo puts focus what goes before it. In the following sentences, the focused information is underlined for the Japanese originals and the literal English translations; for the non-literal English translations, all-caps type emulates how an English speaker would emphasize the focused information.
  • Kono hen ga shizuka da. (この辺が静かだ。; lit. 'This area[, not any other area,] is quiet.', transl. THIS area is quiet.)
  • Kono hen mo shizuka da. (この辺も静かだ。; lit. 'This area, too, [along with at least another area,] is quiet.', transl. THIS area's also quiet.)
  • Kono hen wa shizuka da. (この辺は静かだ。; lit. 'This area? It's quiet.', transl. This area's QUIET.)
  • Kono hen wa shizuka de wa aru ga, fuben da. (この辺は静かではあるが、不便だ。; lit. 'This area? Being quiet? It is indeed, but it's inconvenient.', transl. This area IS quiet, but it's inconvenient)
• Sometimes de and aru can be split quite widely:
  • Ikuji nashi! So shite mattaku sono tōri de watashi wa atta no da. (意氣地なし！　そして全くその通りで私はあつたのだ。; transl. A wuss! I WAS exactly just that.)
• While de nai/arimasen are sometimes used in formal contexts, in ordinary speech ja nai/ja arimasen are used instead. In this case, even though ja is etymologically a colloquially reduced version of de wa, ja nai/arimasen are, functionally, colloquial versions of either de nai/arimasen, which focus on what comes before them, or de wa nai/arimasen which focus on nai/arimasen. Some speakers distinguish the short ja (じゃ) for de and the long jā (じゃあ) for de wa.
  • Marukusu to Renin no shinja de nai desu ka /~ ja arimasen ka (マルクスとレニンの信者でないですか・〜じゃありませんか; lit. 'Are they not believers in Marx and Lenin?', transl. Aren't they BELIEVERS in Marx and Lenin?)
  • Marukusu to Renin no shinja de wa nai desu ka /~ ja(a) arimasen ka (マルクスとレニンの信者ではないですか・〜じゃ(あ)ありませんか; lit. 'Believers in Marx and Lenin? Is that not what they are?', transl. Are they NOT believers in Marx and Lenin?)
• While de (wa) arimasen and de (wa) arimasen deshita are often recommended, de (wa) nai desu and de (wa) nakatta desu are acceptable colloquial alternatives. For the idiosyncratic de (wa) aranai and de (wa) arimashinai, see Negative: Conjugation table.
• De (wa) areba is the regular way of forming conditionals (仮定形, kateikei) in modern Japanese. Naraba (of said nari) is kept as the conditional of da, and along with taraba (of said te ari/te aru → tari/taru → ta), retains the old way of forming conditionals. See #Conditional: Conjugation table for more.
• Desu, a copula of uncertain origin, takes its missing forms from de (wa) aru and de (wa) arimasu, the latter of which is conceivably the ancestor of desu.
• Although nara(ba) (なら(ば)), darō (だろう) and deshō (でしょう) were originally conjugations of da (だ) and desu (です), they are now also used as particles or auxiliaries and can attach directly to other verbs' conclusive/attributive forms, as in kaku nara(ba) (書くなら(ば); 'if one writes'), kaku darō/deshō (書くだろう・でしょう; 'one will probably write'). Desu (or de arimasu or de gozaimasu), deshita and deshō can add politeness the negative auxiliaries ‑n(u) and ‑nai, as well as adjectives:
  • Arimasen/gozaimasen / nai desu/de arimasu/de gozaimasu / naku arimasu / nō gozaimasu ("be not")
  • Arimasen/gozaimasen deshō / nai deshō/de arimashō/de gozaimashō / naku arimashō / nō gozaimashō ("be probably not")
  • Arimasen/gozaimasen deshita / nakatta desu/de arimasu/de gozaimasu / naku arimashita / nō gozaimashita ("were not")
  • Arimasen/gozaimasen deshita deshō / nakatta deshō/de arimasu/de gozaimasu / naku arimashita deshō / nō gozaimashita deshō ("were probably not")
  • Akai desu/de arimasu/de gozaimasu / akaku arimasu / akō gozaimasu ("be red")
  • Akai deshō/de arimashō/de gozaimashō / akaku arimashō / akō gozaimashō ("be probably red")
  • Akakatta desu/de arimasu/de gozaimasu / akaku arimashita / akō gozaimashita ("were red")
  • Akakatta deshō/de arimasu/de gozaimasu / akaku arimashita deshō / akō gozaimashita deshō ("were probably red")
• As shown above, desu does not have its own negative form, and instead borrows de (wa) arimasen from de (wa) arimasu. However, the auxiliary ‑n in de (wa) arimasen in turn does not have its own past and tentative form, therefore deshita and deshō have to be added. The past tentative ‑tarō is infrequent, thus instead of deshitarō, deshita deshō is preferred.

Copulae: Grammatical compatibility

Derived from aru and arimasu, the copulae can have all the forms that these verbs are capable of having. Certain affirmative conclusive and attributive forms have contracted, especially in speech, such as de aru → da/ja and de arimasu → desu; the negative forms remain uncontracted, meaning there is no such form as *daran or *desen.

Imperative: Conjugation table

The honorific godan verbs are originally osshare (おっしゃれ), kudasare (下され), nasare (為され), gozare (御座れ), just like other godan/yodan (四段) verbs, though *irasshare (いらっしゃれ) was not found. These forms are obsolescent and only used for special effect, such as in advertisements. Historically, honorific verbs were nidan (二段) rather than godan/yodan, and western imperative forms like iraserareyo (いらせられよ; → irasshai), ōserareyo (仰せられよ; → osshai), kudasareyo/kudasarei (下されよ・下されい; → kudasai), nasareyo (為されよ; → nasai) are attested. From these nidan verbs, apart from the godan offshoots, there still exist ichidan equivalents. Some rural eastern dialects still have nasaro (為さろ).

With non-godan verbs, there are two imperative forms, one ending in ‑ro and one in ‑yo. ‑Ro has been characterized as used for speech, while ‑yo as used for writing. In actuality, this corresponds to a difference between modern Japanese (口語, kōgo; lit. 'oral language') based on the eastern Tokyo Japanese dialect, and Classical Japanese (文語, bungo; lit. 'literary language'), various literary stages of premodern Japanese based on western dialects. Both ro and yo were interjectional particles in Old Japanese, and were sometimes optional, sometimes obligatory with non-godan verbs. ‑Yo became obligatory with non-godan verbs toward Early Middle Japanese, and its reduced variant ‑i arose during Late Middle Japanese. Historically and dialectally, mi-yo/mi-i/mi-ro/mi (見よ・見い・見ろ・見; 'look!'), oki-yo/oki-i/oki-ro/oki (起きよ・起きい・起きろ・起き; 'get up!'), ke-yo/ke-i/ke-ro/ke (蹴よ・蹴い・蹴ろ・蹴; 'kick!'), ake-yo/ake-i/ake-ro/ake (開けよ・開けい・開けろ・開け; 'open!') (all ichidan), se-yo/shi-yo/se-i/shi-i/se-ro/shi-ro/se/shi (せよ・しよ・せい・しい・せろ・しろ・せ・し; suru, 'do!') and ko-yo/ki-yo/ko-i/ki-i/ko-ro/ki-ro/ko/ki (来よ・来い・来ろ・来; kuru, 'come!') were all possible, with ‑yo and ‑i being the western forms, and ‑ro being the eastern form. The division between western ‑yo/‑i and eastern ‑ro still exists today. According to a 1991 survey:

• ‑Ro dominates eastern dialects.
• ‑Yo is found mostly in central Chūbu and eastern Kyushu.
• ‑I dominates western dialects in Honshu and Shikoku, and marginally in Shitamachi, Tokyo.
• ‑Re, likely as a shortened ‑ro‑i, is found in the northernmost dialects in Hokkaido and the southernmost ones in Kyushu.
• Shiro ("do!") dominates eastern dialects, while sē does western dialects. Seyo and shiyo concentrate in central Chūbu, while sero and sere do in western Kyushu.
• There exist such fused forms as myo(o) (← miyo, "look!"), okyo(o) (← okiyo, "rise!"), akyo(o) (← akeyo, "open!") and sho(o) (← seyo, "do!") in Shizuoka Prefecture and some surrounding areas.
• Koi ("come!") occurs consistently across Japan, although kō has a strong presence in the east. There is a concentration of kē and ke in Kyushu. Koyo is rare in contemporary Japanese dialects, despite being the standard form in classical Japanese. According to another account, koro occurs in an Akita dialect, while kiro is found in Ibaraki. Other variants include kiyo, kī, kui, keyo, etc.
• In some dialects, okiro(o), akero(o), nero(o), koro(o), shiro(o) are actually hortative forms, not imperative forms. The eastern imperative kō also resembles the western hortative of the same verb.

In modern Tokyo Japanese (eastern, specifically Yamanote Japanese), yo largely displaced ro in non-imperative contexts. Yo can be optionally added to modern imperative forms with no historical ‑yo, as in kake yo (書けよ; 'write!'), miro yo (見ろよ), shiro yo (しろよ), koi yo (来いよ); ro can no longer be used this way, although historically it used to occasionally be, as with yodan imperatives like oke ro (置けろ; 'put!') or yome ro (読めろ; 'read!'). Although ‑yo imperatives already contain ‑yo and are primarily "written," it is not impossible for them to be followed by another colloquial yo, as in Kura o akeyo yo (倉を開けよよ; 'Open the storehouse, would you?') or Mō neyo yo (もう寝よよ; 'Just sleep already, would you?'). Apart from the difference between eastern and western dialects, there exists a register difference between ‑yo and ‑ro within standard Japanese. ‑Yo, as the more prestigious classical form of the former western capitals (Nara, Kyoto and Osaka), is still used in formal instructions, such as on test forms, in academic questions, on signage, in formal or polite quoted commands or concessive clauses (spoken or written), etc. On the other hand, ‑ro, as the more colloquially common form, has a connotation of rudeness.

Unlike with most ichidan verbs, ‑ro is optional (possibly dialectal) with kure (呉れ; 'give (me/us)!') and its honorific version okure (御呉れ). Kurero emerged in Edo Japanese during the late Edo period. Yo and i are optionally added, just as to any other imperative form.

Despite originally having the same conjugation as suru, the imperative form of ‑masu(ru) is not *‑mashiro. However, there used to be ‑mase i, with i being the western reduced form of yo. ‑Mase yo exists, though not mandatorily like seyo, but only as ‑mase optionally followed by yo. ‑Mashi is a later variant, characteristic of Shitamachi. It used to be common during the Meiji era, but now has a connotation of unrefined speech. ‑Mase and ‑mashi are meant to be used with honorific verbs, as in irasshaimase (いらっしゃいませ), nasaimase (為さいませ), asobashimase (遊ばしませ), meshiagarimase (召し上がりませ), etc, and not with ordinary verbs like *kakimase (書きませ) or *arukimase (歩きませ).

The modern western ‑i imperative has made its way to Tokyo in the "downtown" region of Shitamachi. When it is preceded by the vowel e, the resulting form is ē, ei or even e, in keeping with the common realizations of such combination (see Japanese phonology § Vowel sequences and long vowels), hence se(e)/sei (= shiro/seyo) and ake(e)/akei (= akero/akeyo). In Kyushu, koi can be similarly smoothed out into ke(e) (compare the Tokyo variant sugē of sugoi (凄い; 'awesome'); more at #Imperfective: Conjugation table). Like yo, i can further attach to, among others, godan/yodan imperatives, as well as eastern ‑ro imperatives, for example in “Ya, batta da. Ōbatta tore ih.” (「や、バッタだ。大バッタとれいッ。」; '“Look, a grasshopper! Catch the big grasshopper!”'), totto to oriro i. (とっととおりろい。; 'get off quickly!'), Akero i = Akero yo (開けろい; 'Open up!'), etc; the particle ya, which can otherwise follow imperatives just like yo, with a potential masculine ring, as in Yose ya i (止せやい; 'Cut it out!'), Hakkiri ie ya i (はっきり言えやい; 'Speak clearly!'), etc; and negative commands with na following conclusives, as in Yokei na kuchidashi o suru na i. (よけいな口だしをするない。; 'Don’t butt in needlessly!'). It is also found in non-imperative constructions such as ka i (question marker), da i (copula), ‑ta/‑da i (perfect), although it has been said to be a variant of ne in these cases rather than of yo.

The older and more classical koyo ("come!") is rare in modern spoken dialects, but it was sometimes used as the written version of koi; for example, the linguist Kasuga Masaji used koyo while analyzing nursery rhymes that contain koi.

Gozai and gozare are used as a more polite way to say "come!" instead of koi (来い). They also occur in the concessive idiom nan de mo gozai/gozare (lit. 'come anything', transl. anything goes; anything's good; anything imaginable), which is synonymous with nan de mo koi. De gozare is a more polite equivalent to de are.

Are and de (wa) are have limited use in formal contexts, for example Kami mo shōran are (神も照覧あれ; 'may God be my witness'), hikari are (光あれ; 'let there be light'), Ito takaki tokoro ni wa eikō, Kami ni are, chi ni wa heiwa, mikokoro ni kanau hito ni are. (いと高きところには栄光、神にあれ、地には平和、御心に適う人にあれ。; 'In the highest realm, glory be unto God, on earth, peace be unto those who earn his grace.'), itsu mo Kami ni shitagatte are. (いつも神に従ってあれ。; 'always be obedient to God.'), shōjiki de are (正直であれ; 'be honest'). De (wa) are also has a concessive use, as in Riyū wa nan de are, bōryoku wa yoku nai yo. (理由は何であれ，暴力はよくないよ。; 'No matter the reason, violence is not good.'), Nan no heya de are, mō koko ni tomete morau hoka wa nai (何の部屋であれ、もうここに泊めてもらうほかはない; 'Whatever the room may be, we have no choice but to stay here.'). This has been linked to a probable contraction from the identically sounding conditional base, de are, preceding the concessive particle ‑do, as in de aredo. However, unambiguously imperative bases in ni seyo and ni shiro also have concessive uses, as in Sanka suru ni seyo, shinai ni seyo, toriaezu renraku o kudasai. (参加するにせよ，しないにせよ，とりあえず連絡を下さい。; 'Whether you partake or not, please get in touch soon.') and Soba ni shiro, udon ni shiro, menrui nara nan de mo ii n da. (そばにしろ，うどんにしろ，麺類なら何でもいいんだ。; 'Soba, udon, whatever, any kind of noodles will do.')

Unlike are, adjectival imperative forms derived from fusions with it (‑ku are → ‑kare) seem to be used mostly for concession, as in ōkare sukunakare (多かれ少なかれ; 'be there more or less'), takakare yasukare (高かれ安かれ; 'be it expensive or cheap'), tsuyokare yowakare (強かれ弱かれ; 'be it strong or weak'), osokare hayakare (遅かれ早かれ; 'be it later or sooner'), yokare ashikare (良かれ悪しかれ; 'be it good or bad'), tōkare chikakare (遠かれ近かれ; 'be it far or near'), etc and occasionally for elevated wishes, as in Yasukare (安かれ; transl. May you be at peace) or Sachi ōkare (幸多かれ; transl. Best of luck to you). The exceptional nakare ("let there not be") expresses elevated and/or motivational negative commands or wishes, as in Ogoru nakare! Jimintō (驕るなかれ！自民党; transl. Do not be prideful! O, Liberal Democratic Party), Taka ga benpi to yū nakare (高が便秘と言うなかれ; transl. Don't say it's just constipation), etc. The phrase koto nakare (事なかれ; lit. 'let there be no incident') is used in koto nakare shugi (事なかれ主義; 'principle of not rocking the boat'). Nakare behaves syntactically like the negative imperative particle na, which is similarly placed after an attributive/conclusive verb, thus ogoru na (驕るな; 'don't be prideful'), yū na (言うな; 'don't say'), etc. Unfused ‑ku are forms have also been found, as in kiyoku are (清くあれ; 'be pure!').