Historically, the vowel
u systemically fused with its preceding vowel into one long vowel, which yielded such pronunciation as . These fusions are complete in some western dialects, but others still make exceptions for verbs ending in
u. Compare the following, whereby the unfused forms are listed first: , , , . In
classical Japanese, the fused forms are traditionally used, regardless of the kana spelling, which is the case for not only the said example
godan verbs, but also
nidan verbs such as , although modern Tokyo speakers may rather use the
spelling pronunciation kangau. Some highly elevated verbs such as and accept the fused forms as standard rather than dialectal alternatives. Despite the pronunciation, its standard kana spelling is still , not , (although the latter is still listed in dictionaries,). This convention, along with the particles , and , is retained from
historical kana orthography for practical purposes. For , the kana spelling is in keeping with other conjugational forms such as and . is possibly
homophonous with ,
Aru is now a full-fledged
godan verb, but it used to belong to an irregular class called in
classical Japanese. Although having been long displaced by its attributive
aru, its distinct conclusive
ari lingers on in some proverbial cliches, such as , , etc., or the pseudoclassical baseball cliche .
Certain ‑suru or ‑zuru verbs and their
godan and
ichidan equivalents are interchangeable (or at least sensitive to specifically what follows them) and even used in the same text, although it has been claimed that, at least for the conclusive/attributive form, the more classical//western
‑zuru variants are more "formal" and "basically a written form", compared to the more modern//eastern
‑jiru variants. The
‑su variants are highly inconsistent across verbs, and even for highly "
godan‑ized" verbs like , whose other forms are predominantly
godan, the conclusive/attributive
aisuru and
conditional aisureba in particular are still preferred to the fully
godan variants
aisu and
aiseba. In some cases it is not clear whether
aisu is
godan or actually pseudo-classical, for example in where all
‑suru verbs can optionally lose the
ru. In classical or pseudo-classical literature,
aisu is more likely to be conclusive and
aisuru is more likely to be attributive or nominalized. The extenders
beshi,
beki,
beku,
mai,
maji,
majiki,
majiku, etc., can stylistically take classical conclusives before them, including the irregular and , and the
nidan , , , , etc. These can be substituted with the modern irregular and , and the
ichidan , , , , etc. Some governmental institutions have shifted away from the
nidan style () in favor of the
ichidan style (). With the classical irregular conclusive and its derivatives, however, the attributive is used instead, as in , , etc. rather than *
ari beki, *
yokari beki, etc., and such exceptions coincide with the modern
godan conclusives ending in
aru of the same verbs and adjectives. and , may have two
ichidan counterparts for each, one being
kamiichidan ("upper unigrade") with the vowel
i, and the other being
shimoichidan ("lower unigrade") with the vowel
e, and they may differ in transitivity, which is made morphologically obvious in the
ichidan conclusives, attributives and provisionals compared to their
nidan ancestors. Since
nidan verbs can be used before extenders, so-called "
yodan verbs" presumably can as well, but as their conclusives/attributives are indistinguishable from so-called "
godan verbs," it is rather a matter of classical fused pronunciation versus modern unfused pronunciation than truly distinct verb forms. The classical forms of the now
ichidan verb are
deku and , which belong to the same irregular class as
ku and . While
deku can be used before
beki, etc as in
deku beki, etc, it is also possible to use the
infinitive deki instead as in
deki beki, etc. The verb is now a full-fledged
godan verb in mainstream Japanese, but it used to belong to its own irregular class () with the now obsolete . It had a distinct attributive and provisional which have been used elevatedly. The classical attributives of
‑ta/‑da are
‑taru/‑daru, which have been used elevatedly just like
nidan attributives (compare the copular attributive
na(ru)). The classical
‑tari/‑dari are not really used conclusively as true conclusives, where the modern
‑ta/‑da are still preferred; the formally identical infinitives
‑tari/‑dari evolved into modern
representatives. The politeness auxiliary
‑masuru is characterized as "pseudo-literary" or faux archaic. It was used in parliamentary speech during the 20th century, but usage drastically declined into the 21st century. Some examples include , , . The conjugational similarity between
‑masu and
suru suggests an etymological link. The sound sequence , with /V/ being a vowel, is often colloquially and masculinely fused into a long vowel. Since all adjectival conclusive/attributive forms have this sound sequence, they are liable to such fusion. Most adjectives of this kind remain distinctly masculine, and their phonetic spellings are found in written dialog for masculine characters in fiction, such as , , , , , , , , , , etc. Non-masculine examples include , and . See for further citations. The classical conclusives
nashi and
yoshi in particular are now more of cliches rather than catch-all representatives of adjectives in general.
Nashi is often used as a nominal suffix meaning "without", "‑less" or "‑free", as in .
Yoshi is often used as an interjection meaning "Good!" or "Alright!". The classical
onaji has evolved into an
adjectival noun (
onaji da/de aru/desu,
onaji (na), etc.), and despite being originally conclusive, it is now prevalently attributive. Other examples of classical conclusives for cliched, proverbial and elevated uses include , , , , etc. The classical attributive ending
‑ki, the ancestor of the modern attributive/conclusive ending
‑i, is still used in elevated cliches and titles for books and fictional characters, such as , , , , , , etc. The attributive ending
‑karu, a fusion of the
infinitive ending
‑ku and the verb
aru, is uncommon in modern Tokyo Japanese. It has been found in such constructions with
‑beki as . In
Kyushu,
‑karu was reduced further to
‑ka, and
yoka is used instead of either
yoi or
yoshi. The classical adjectival extenders
beshi,
gotoshi and
maji are still used in elevated language. Their attributives retain the
‑ki ending as in
beki,
gotoki,
majiki, although the
‑i ending as in
bei,
majii has historically and dialectally occurred. For
beshi in particular, its attributive
beki can be used conclusively in the phrase
beki da/de aru/desu. For more examples, see #Imperfective: Grammatical compatibility below. == Grammatical compatibility ==