Is verb ending ない shortened to ん?


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
>
> 絶対許さん!

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

> もう我慢できん
>
> 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?




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.~~

**Edit:**

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.




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.~~

**Edit:**

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.

