24494
Upon looking up the term
[大事ない](http://dictionary.goo.ne.jp/srch/jn/%E5%A4%A7%E4%BA%8B%E3%81%AA%E3%81%84/m0u/),
I was, shall we say, nonplussed to learn that it could mean both ["very
important"](http://dictionary.goo.ne.jp/leaf/jn2/133324/m0u/%E5%A4%A7%E4%BA%8B%E3%81%AA%E3%81%84/)
and ["not very
important"](http://dictionary.goo.ne.jp/leaf/jn2/133325/m0u/%E5%A4%A7%E4%BA%8B%E3%81%AA%E3%81%84/).
The explanation of the "very important" meaning clears things up, though - the
ない here is not 「無い」, but rather [the "emphatic" 接尾語
「ない」](http://dictionary.goo.ne.jp/leaf/jn2/162272/m0u/%E3%81%AA%E3%81%84/).
This is super-interesting, and explains why words like 切ない do not "mean"
"切無い", which is something that had always bugged me.

What is the etymology of this "emphatic" ない? Is it related to the classical
copula なり?
CC BY-SA 3.0
2015-05-24T02:07:26.060
24490
2015-11-11T01:47:39.043
3437
question
etymology
What is the etymology of the "emphatic" ない?
Just to respond to the question part, the origin of the "emphatic" ない is the
Classical suffix 「なし」, and not 「なり」.

<http://kobun.weblio.jp/content/%E3%81%AA%E3%81%97>

「なし」 is an adjective-forming suffix with the meanings of "truly ~~",
"extremely ~~", etc.

It needs to be noted again that this has **_nothing_** to do with 「[無]{な}し」.
CC BY-SA 3.0
2015-05-24T09:11:35.627
24494
2015-05-24T09:11:35.627
24490
answer
As l'électeur notes, the emphatic ない in 大事【だいじ】ない, 切【せつ】ない, and the like comes
from older なし, and is an adjectival suffix indicating " _having XX quality or
state_ ", where _XX_ is the preceding root word. In terms of meaning, this is
definitely **not** the same _nashi_ as 無し.

There is a growing body of research, including recent works by Bjarke
Frellesvig, building on the idea that Old Japanese had a copular verb ぬ. The
emphatic ない is probably related to this in some way -- a number of other old
root verbs have counterpart adjectives following the same vowel-shift pattern,
such as あく > あかい, たく > たかい, なぐ > ながい.

Negative ない appears to have grown out of negative ぬ somehow. Although the
exact derivation is unclear, the resources I've looked at (Shogakukan,
Daijirin, Daijisen, among others) all agree on this point. Negative ない as a
verb ending appears as an eastern-Japanese term from the late [Muromachi
period](http://en.wikipedia.org/wiki/Muromachi_period).

Negative ぬ must follow the incomplete form (未然形【みぜんけい】) of a verb. If it
follows the stem or compounding form (連用形【れんようけい】), it instead indicates
completion or resulting state -- essentially the same as emphatic ない.

### Speculation

This leads me to think that the negative connotations of ない originally arose
from the incomplete or inchoate senses inherent to the incomplete conjugation
of verbs. In my own research, it thus appears that negative ない and emphatic ない
both arise from this same ぬ copula in Old Japanese.
CC BY-SA 3.0
2015-11-10T22:54:56.873
29151
2015-11-11T01:47:39.043
2015-11-11T01:47:39.043
5229
5229
24490
answer