Causative-Passive Verbs: Vせられる and Vされる


Looking at the answer to [this
question](https://japanese.stackexchange.com/questions/15157/is-%E8%A1%8C%E3%81%8B%E3%81%95%E3%82%8C%E3%81%9F-a-
typo/15159#15159), it seems that both 行かせられる and 行かされる are valid forms of the
causative-passive of 行く. I've only been taught the first usage, so I have a
number of related questions regarding the difference between the two.

Is the second form a contraction of the first? Is there any difference in
nuance between the two? Is the impression that they give when used any
different between the two?

Can all 五段 verbs follow this pattern? For example, could 読ませられる be replaced
with 読まされる? If this usage is due to a contraction, is there a similar pattern
for 一段 verbs? For example, would 出させられる be able to be replaced with an
alternate version?

Which usage is used most frequently? And is the same usage used in spoken
language as in writing (such as in novels)?




More detail about how the causative and passive suffixes evolved.

The causative ( _-a_ )せる arose from just plain old す ( _su_ ), itself the
origin of the ubiquitous modern verb する ( _suru_ , "to do"). The original
meaning was "to do [something]; to make XX do [something]" -- i.e., this
served as a causativizing or transitivizing suffix.

Meanwhile, the passive ( _-a_ )れる similarly arose from just plain old る ( _ru_
). The original meaning was "[something] happens" -- i.e., this functioned as
a passivizing or intransitivizing suffix.

In both cases, the root monosyllabic 助動詞 ( _jodōshi_ , auxiliary verb) had the
classical Japanese conjugation pattern called 下二段 ( _shimo nidan_ , "lower
two-step"). The "lower" part means the conjugated verb ending alternates
between _u_ and _e_ , contrasting with 上 ( _kami_ , "upper") verbs that
alternate between _u_ and _i_. As Japanese developed, the root suffix was
later conjugated into the 未然形 ( _mizenkei_ , incomplete form) of せ or れ, with
the verbalizing suffix る added onto the end again.

For modern 五段 ( _godan_ , "five step") verbs (so called for the five different
vowels that can appear on the end of the verb stem during conjugation), the
old root form す can still persist for the causative, resulting in valid
grammatical forms like いかす for いかせる, or のます for のませる.

(Note that sometimes the resulting causative form might sound identical to
another verb, such as 置かす _okasu_ "to make someone put something somewhere",
which sounds identical to 犯す _okasu_ "to violate, to rape". In such cases, the
fuller causative form of 置かせる _okaseru_ is probably preferable.)

As such, 行かす is not actually a contraction of 行かせる, and is instead the older
form.

* * *

The causative and passive endings attach to the 未然形 ( _mizenkei_ ,
[irrealis](https://en.wikipedia.org/wiki/Irrealis_mood) or incomplete form) of
the verb stem.

For _godan_ verbs, the _mizenkei_ is the stem form ending in _-a_ , such as 行か
( _ika_ ) for 行く ( _iku_ ), 積ま ( _tsuma_ ) for 積む ( _tsumu_ ), etc. The
passive in classical Japanese was just る for _yodan_ verbs (the precursor to
modern _godan_ verbs), developing later into れる, by the same _mizenkei_ + る
pattern described below for 出る ( _ideru_ ). Similarly, the causative was just
す, developing later into せる as _mizenkei_ + す.

For _nidan_ (only found in classical Japanese) and _ichidan_ verbs, where the
_mizenkei_ stem is the same as the _ren'yōkei_ (continuative) stem, the
passive in classical Japanese was らる, developing later into られる. The causative
was さす, developing later into させる.

* * *

As an aside, the す・る dichotomy for transitive / intransitive persists in
numerous modern verb pairs, such as 出る ( _deru_ , to go out) and 出す ( _dasu_ ,
to put something out). These two verbs originate from the now-obsolete root
verb 出づ ( _idzu_ , possibly _idu_ in even older stages of the language). This
verb was also a _shimo nidan_ verb. The classical passive or explicitly
intransitive form of a verb is [stem in _mizenkei_ ] + る. For _idzu_ as a
_shimo nidan_ verb, this would be _ide_ + _ru_ , forming _ideru_. Over time,
the initial _i-_ dropped off, producing modern _deru_.

The causative or explicitly transitive form of _idzu_ **should** be [stem in
_mizenkei_ ] + す, or _ide_ + _su_ = _idesu_ , but this pattern is slightly
irregular and produced _idasu_ instead, later shortening to _dasu_. (The
_shimo nidan_ causative / transitive pairs like this that I've looked at all
take _-eru_ and _-asu_ , instead of the expected _-eru_ and _-*esu_.)

Other transitive / intransitive pairs like this include:

  * 増える / 増やす ( _fueru_ / _fuyasu_ ), "to grow or increase by itself" /"to make something grow or increase" ( _shimo nidan_ root)
  * 溶ける / 溶かす ( _tokeru_ / _tokasu_ ), "to melt or dissolve by itself" / "to make something melt or dissolve" ( _shimo nidan_ root)
  * 漬かる / 漬かす ( _tsukaru_ / _tsukasu_ ), "to be in a liquid; to become pickled" / "to stick something into a liquid; to pickle something" ( _godan_ root -- つく -- regular passive / causative formation, with idiomatic development over time)

* * *

**TL;DR** : Long story shorter, non- _godan_ verbs cannot take the shorter
causative form of す ( _su_ ) or the shorter passive form of る ( _ru_ ), due in
part to historical development, and due in part to other related verb forms
that already take a bare す or る.

