100715
Does anyone know what でしょう originally comes from?

And are those forms ever used nowadays?
CC BY-SA 4.0
2023-08-19T06:15:18.310
100712
2023-08-20T17:18:04.603
57315
question
etymology
Etymology of でしょう?
だ and です are modern contracted copulae (verbs "to be"), they developed in Late
Middle Japanese.

だろう and でしょう are Conjectural/Tentative forms of these copulae, formed slightly
irregularly.

Old Japanese suffix _-(a)m-_ is called Conjectural by Frellesvig (2010),
Tentative by Vovin (2020).

Frellesvig (2010, "A History of the Japanese Language", page 78) in chapter
about Old Japanese:

> 3.1.4.10 Conjectural and subjunctive
>
> The _conjectural_ belongs to the QD conjugation. The _subjunctive_ has its
> own conjugation, the few forms of which resemble the simple past.
>
> The conjectural is the least specific of the modal auxiliaries and is very
> frequent in the OJ texts. Its uses fall into two overall categories: (a)
> _conjecture_ : probability and necessity; (b) _volition_ : intention and
> wish. Note that the combination of the simple past and the conjectural
> _-kye-m-_ is used only to express conjecture 'probably was, probably did',
> not volition. Like modals in many languages, the conjectural can also be
> used to refer to future time with little or no modal meaning; the
> conjectural is therefore sometimes termed a 'future tense'. Followed by the
> conjunctional particles _to_ or _ni_ it is used to form purposive adjunct
> and complement clauses 'that, so that'.

Highly defective simple copula was/is [ _nə_ ( _no_ since EMJ), _ni_ , _nite_
(→ LMJ/NJ _de_ )]. Since it was defective, it did not have many forms, and it
participated/participates in constructions with other verbs ( _ar(i|u)_ ,
_imasu_ ), which allow full inflection. (That verb
[_imasu_](https://en.wiktionary.org/wiki/%E3%81%84%E3%81%BE%E3%81%99), now
archaic or extinct, should not be mistaken with _-masu_ form of modern verb
_iru_ , which comes from OJ/EMJ _wiru_.)

Main extended copula in Old Japanese and at least Early Middle Japanese was
formed with verb _ar(i|u)_ : _**ni ar(i|u)**_ , and its contracted form
_**nar(i|u)**_.

Conjectural/Tentative form of copula _ni ar(i|u)_ / _nar(i|u)_ in Old Japanese
and early Early Middle Japanese was: _**ni aramu**_ / _**naramu**_.

In Late Middle Japanese, extended copula _**de aru**_ developed. It contains
the same verb _aru_ (earlier _ar(i|u)_ ) as older aforementioned _ni ar(i|u)_
/ _nar(i|u)_ , but contains different form of defective simple copula: _de_
instead of _ni_. Modern copula _**da**_ developed as contraction of _**de
aru**_.

There were/are other similar constructions in LMJ/NJ, e.g. _**de gozaru**_
(currently used in samurai-style speech).

One of now extinct constructions was with verb
_s[ɔ](https://en.wikipedia.org/wiki/Open-mid_back_rounded_vowel)ːrɔː_: _**de
sɔːrɔː**_. Modern polite copula _**desu**_ is considered (by at least some
linguists) to be contraction of _**de sɔːrɔː**_.

* * *

Phonological development of Conjectural/Tentative suffix _**-am-**_ +
Conclusive/Terminal/[終止形]{しゅうしけい} _-u_ :

  * For consonant-stem verbs:

/-amu/ → /-a[ũ](https://en.wikipedia.org/wiki/Nasal_vowel)/ → /-au/ →
/-[ɔ](https://en.wikipedia.org/wiki/Open-mid_back_rounded_vowel)ː/ →
/-[o](https://en.wikipedia.org/wiki/Close-mid_back_rounded_vowel)ː/

Example for _kaku_ (書く):

/kakamu/ → /kakaũ/ → /kakau/ → /kakɔː/ → /kakoː/

  * For _e_ -vowel-stem verbs (initial _a_ of _-amu_ suffix was elided):

/-emu/ → /-eũ/ → /-eu/ → /-joː/ → (regularization) /-ejoː/

Example for Old/Middle Japanese _nu_ , modern 寝る:

/nemu/ → /neũ/ → /neu/ → /njoː/ → (regularization) /nejoː/

  * For _i_ -vowel-stem verbs (initial _a_ of _-amu_ suffix was elided):

/-imu/ → /-iũ/ → /-iu/ → /-juː/ → (regularization) /-ijoː/

Example for Old Japanese _mi_ , Middle Japanese _miru_ , modern 見る:

/mimu/ → /miũ/ → /miu/ → /mjuː/ → (regularization) /mijoː/

  * For irregular vowel-stem verbs (initial _a_ of _-amu_ suffix was elided):

Verb _kə-_ → _ko-_ (Conclusive/Terminal/[終止形]{しゅうしけい} _ku_ , modern _kuru_
(来る)):

/kəmu/ → /komu/ → /koũ/ → /kou/ → /koː/ → (regularization) /kojoː/

Verb _se-_ (Conclusive/Terminal/[終止形]{しゅうしけい} _su_ , modern _suru_ (する)):

/semu/ → /seũ/ → /seu/ → /sjoː/ → (regularization) /sijoː/

Forms with nasal vowel /ũ/ existed for some time in Early Middle Japanese.
During this period, there were also other variants of development of original
/mu/, which ultimately did not survive.

Fusion of consecutive vowels into long vowels occurred in Late Middle Japanese
and was not specific to this suffix, it occurred also in many other words.

Europeans arrived to Japan in 16th century, and distinction between 2 types of
long vowel _o_ , assumed to be [low-mid
/ɔː/](https://en.wikipedia.org/wiki/Open-mid_back_rounded_vowel) and [high-mid
/oː/](https://en.wikipedia.org/wiki/Close-mid_back_rounded_vowel), is attested
in European sources about Japanese language from 16th/17th century. /ɔː/ and
/oː/ merged into /oː/ in Early Modern Japanese.

Regularization of forms of this suffix for vowel-stem verbs occurred in Modern
Japanese (maybe middle/late Edo period).

* * *

When _**desu**_ appeared, we would rather expect that its
Conjectural/Tentative form be _***/desɔː/**_ (＊でさう) → _***/desoː/**_ (＊でそう),
but _**/des joː/**_ (modern hiragana spelling でしょう) was created probably by
analogy with Conjectural/Tentative form of verb す／する, which was /sjoː/ at that
time.
CC BY-SA 4.0
2023-08-19T10:58:01.753
100715
2023-08-20T17:18:04.603
2023-08-20T17:18:04.603
56758
56758
100712
answer