Something I became more aware of than before is that most of the humble as well as honorific verb forms that we find in modern Japanese, along with several fixed expressions come off as completely irregular within Tokyo Japanese, but are actually the regular outcome of such verbs in (an early version of) Kansai Japanese. This is no surprise, as Kyoto and the larger region was the start if Japanese high culture, and most of the written history of Japanese is in fact in this dialect. That expressions and forms would be borrowed, especially in the formal registers and fixed phrases is thus hardly surprising.
Adverbs of i-adjectives
In SJ (Standard Japanese) the adverbial form of the so-called i-adjectives is -ku, e.g. hayaku 'early, quickly'. In the Kansai dialects however, intervocalic *k is lost before *u/i (regularly? or irregularly? at least regularly in this type of adjective) yielding *hayau which subsequently monophthongized regularly to *hayō. This then gives an explanation for a whole set of formal expressions that don't make sense in SJ:
o-hayō gozaimasu 'good morning' < *o-hayaku goza(r)imasu
o-medetō gozaimasu 'congratulations' < *o-medetaku goza(r)imasu
arigatō gozaimasu 'thank you' < *arigataku goza(r)imasu
The negation of the 'polite' suffix -masu
The suffix -masu (or perhaps more properly: polite auxiliary verb) is added to verbs to make them more polite: aru'to exist' arimasu'to exist (polite)'. Its negation, however, is irregular. Rather than the expected **masa-nai we get -mase-n, even in modern Kansai dialects that negation would be unexpected, we would rather expect *masa-n, however historical insight into the suffix shows that it was originally a "shimo ni-dan" verb. Most shimo ni-dan verbs end up in the SJ ichidan class, verbs that have an unchanging base-stem to which in the unmarked form a suffix -ru is added such as tate-rutate-masu tate-nai'builds; builds (polite); doesn't build'. However, there used to be forms where there was some overlap between the normal verbs, namely in the conclusive form.
So in Middle Japanese a verb like tateru would have been tat-u in its "conclusive" form, but tate-ru in its attributive form. When the conclusive an attributive merged (as they already had in the standard verbs) this overlap was lost. But for the polite suffix, rather than becoming mase-ru in both the conclusive and attributive form, it rather kept the conclusive form for both: mas-u but its negation still betrays its old (and non-SJ origin); -mase-n is the regular negation of a Kansai dialect shimo ni-dan verb.
The volitional form of the 'polite' suffix -masu
Another leftover of the shimo ni-dan origins of the masu verb, is its volitional form. The volitional used to originally be made by adding -(a)u to the verb. -au subsequently contracted into ō. Hence we get *hanasau 'let's talk' > hanasō.
But the volitional form of -masu is not **hanasi-masō but hansi-masyō. As we discussed in the previous blog post, eu yielded yō in SJ. Hence a stem *mase-(a)u yielded > maseu > masyō. This conjugation has been completely reformed form the shimo ni-dan verbs in SJ, where a verb like mise-ru'to show' would have a volitional form mise-yō not **misyō. The Kansai dialect still has a leftover of this behaviour in the volitional form of suru which is syō the regular outcome of *se-(a)u, rather than the SJ siyō.
The conjugation of honorific verbs with stem-final -r
A element that must be related to the honorific/polite system being based on the Kansai dialect rather than the Tokyo dialect of SJ must also lie at the basis of an unusual irregularity of the stem final -r verbs. However, the exact development of this is not completely clear to me. The regular conjugation of verbs that have a stem-final r followed by the polite suffix -masu is simply -r-i-masu. e.g. ar-u> ar-i-masu. However, a group of honorific verbs have a different conjugation, where the r is lost:
gozar-u> goza-i-masu 'to exist'
kudasar-u> kudasa-i-masu'to give'
irassyar-u> irassya-i-masu'to go/come/exist'
ossyar-u> ossya-i-masu'to say'
nasar-u> nasa-i-masu'to do'
All of these verbs are presumably originally univerbated combinations of a verb + the auxiliary ar-u'to exist. And while ar-u is an irregular verb that behaves different from all other verbs of this shape in Middle Japanese, the irregularity is not the loss of an r before i. To my knowledge, this is not regular behaviour of the verb ar-u in the Kansai dialect either; but I would love to be corrected. Either way, finding the conjugation of a verb type being different specifically in its honorific verbal system, does point to the strange 'layered' effect of the honorific/polite system that seems to be importing its morphology from a different linguistic stratum than the rest of the verbal system.