Off the top of my head I remember hearing these sentences, which I assume are just shortenings:

すみません, 分からん


Along with these two I've seen in sentence examples:


彼にはその文の意味が理解できんかった - this one is a little funky, since there is no complete ない->ん conversion, but instead なかった->んかった

Is this kind of shortening common? Can one always shorten a verb-ending ない to ん?


2 Answers 2


The ん negative ending is a contraction of sorts of classical negative ending ぬ, precursor to modern ない. It's still pretty common. As illustration of this, the Microsoft IME gives 食べん as a valid conversion option after typing in taben, or 飲まん for noman.

Note that する with the negative ん is not しん, but instead せん, as again the negative ん is from classical ぬ, and the classical negative form of する is せぬ.

(蛇足: I think this せん was another layer of pun in the shortened name of the title character in Spirited Away.)

In addition, the ん in the polite negative ending ません is this same ぬ > ん contraction. ます for the most part conjugates in a similar way as する, with the classical negative ませぬ.

Occasionally, modern ない itself will contract to just ん without coming from the classical ぬ, as in the common informal contraction じゃん from ではない, or as in the なかった > んかった shift mentioned in the question. As a verb ending, though, negative ending ん is usually from classical negative ぬ.


じゃん is sometimes explained as a contraction of ではない, where では becomes じゃ and ない becomes ん. Phonologically, the first half is well-established and accepted where で + は shifts to じゃ, but the ない > ん shift remains unexplained. A more likely sound shift would be based on the older phrases ではあらぬ or ではあらむ. あらぬ aranu is the older verb-based version of modern negative ない nai, meaning "[there | it] isn't", while あらむ aramu with an m sound is the older version of modern presumptive あろう arō, meaning "isn't [there | it]", confirming with the listener.

Semantically, modern じゃん is used either in a negative sense, or in a confirmation sense, matching these two older verb forms.

Phonetically, both あらぬ and あらむ were known to contract to あらん aran. So ではあらぬ / ではあらむ > じゃあらん. The corruption of -あらん to -あん can be observed in the slang of some modern speakers, such as 分からん > 分かん. So じゃあらん > じゃん.

So ultimately, I don't think there is any diachronic (i.e. historical) foundation for ない itself turning into ん directly. Instead, we see the precursor to ない, classical ぬ, turning into ん via clearly observable contraction processes.

  • 1
    @Erikr Utlendi: This is a very informative answer but do you have any comment on how it is most commonly used among speakers of 標準語? Off the top of my head I would have said it was for concluding sentences in abrupt decisive manner.
    – Tim
    May 31, 2014 at 0:16
  • Ah, yes, in terms of social register, this is a step below the plain ない ending: more informal, more casual. My sense is that this is not necessarily decisive, but definitely informal. Consider two friends talking: 「公園に行く?」「分からん。宿題もあるし。」 Here, 分からん could be construed as similar to English dunno: informal speech, but not necessarily rude if used in the correct social context. May 31, 2014 at 0:25
  • Also, Kansai still keeps the older ぬ, while already quite long ago Kantō started using ない. In fact Kantō never ever used ぬ as the negative: the classical one was なふ (conjugated as 四段, some believe ない came from the 連用形 of that). So it seems very likely ん is a (contraction of a) Kansai loan, and gets all the connotations Kansai loans get.
    – ithisa
    May 31, 2014 at 1:43
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    Given the differences in conjugation, and the sizable historical lacuna, I'm much more inclined to think that auxiliary nai from older nashi was basically as use of the adjective, rather than as any direct derivative of nafu. I'm certainly open to the possibility that nashi arose as some kind of adjectivization of nu. I am also quite curious now as to what was used to mark negatives in the Kantō between the last citation of nafu and the first citation of nashi. Jun 2, 2014 at 19:34
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    Unfortunately people seemed to stop writing down Kantō Japanese after the Old Japanese period, with standard Classical Japanese being purely based on Kansai Early Middle Japanese.
    – ithisa
    Jun 5, 2014 at 2:10

It is 〜ない being shortened to 〜ん, but only under certain circumstances. Specifically, it's in cases where Type I verbs ending in 〜る use the 〜ない form. For example:

  • 分からない -> 分からん
  • 知らない -> 知らん
  • 蘇らない【よみがえらない】 -> 蘇らん

Also related to this is 〜aんない, which is more of a simple slurring wherein ら gets dropped. For example:

  • 分からない -> 分かんない
  • 知らない -> 知んない
  • 蘇らない -> 蘇んない
  • For the curious, my IME did produce the forms for 蘇る without any difficulty. Wanted a third example verb and it was the first one that came to mind offhand. Slightly surprising one, really, since most -eru verbs are Type II...
    – Kaji
    May 31, 2014 at 0:31
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    蘇る is a compound, derived from 黄泉{よみ} "land of the dead" + 帰{かえ}る "to return from somewhere". Since source verb 帰る is 五段, so too is 蘇る. May 31, 2014 at 0:37
  • Ah, that makes sense. I'd never known the etymology for it previously.
    – Kaji
    May 31, 2014 at 0:43
  • The ん in じゃん may be from ない, but the verb-ending ん doesn't appear to be. Shogakukan's etymology for verb-ending negative ん notes: 「打消の助動詞「ず」の終止形と連体形とが共に「ぬ」となり、その変化したもの」. The pattern of ぬ changing to ん also agrees with established phonetic shifts in Japanese, whereas there is less of a clear mechanism for ない to become ん. For that matter, あらぬ was used classically as the negative for ある, so じゃん could conceivably derive from ではあらぬ instead of ではない, which would make more sense phonetically. May 31, 2014 at 0:45
  • @EiríkrÚtlendi: FYI, よみ can also be written as 陰府.
    – istrasci
    Jul 17, 2014 at 18:16

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