Transitive vs Causative Intransitive


> original (Causative Intransitive): 彼女は私の肩に頭を凭れさせる

vs

> new (transitive): 彼女は私の肩に頭を凭せる

[way back when i asked
this](https://japanese.stackexchange.com/questions/50276/use-of-the-causitive-
form-without-an-obvious-source-of-causation), i took it as sometimes there is
no transitive pair for an intransitive verb so the causative is used to take
direct object with を (like with はためく?).

Looking back on it this most of these definitely have a transitive pair, so
what is the difference then?

can be applied to this from the link:

> (original) レンズをあちこちに巡らせる vs レンズをあちこちに巡らす。




According to [this article](http://www.nkg.or.jp/wp/wp-
content/uploads/2018/04/113_causativeandtransitiveverbs.pdf), there are a few
main differences.

One difference is that if the thing that is being caused to do something is
inanimate, it can sound unnatural:

> ✖品物を並ばせる
>
> 〇品物を並べる
>
> ✖切手を集まらせる
>
> 〇切手を集める

The reason for this is that the causative construction implies a willingness
of the thing that is being caused to do something to do that action. So
because of this, in your example, レンズをあちこちに巡らす is probably the more natural
construction.

Another difference is that there is a difference in meaning:

乗客を降りさせる = `make the passenger get off the vehicle`

乗客を降ろす = `let the passenger get off the vehicle`

In the former, the driver or whoever causes the passenger to be motivated to
get off the vehicle. The latter is a routine thing in that the passenger is
just let get off.

_**Edit:**_

_Semantics of Japanese Causativization_ (1973) gives the following example for
the difference between the transitive and the causative intransitive when the
direct object is inanimate.

> ａ．太郎が車のエンジンを止めた。

This is used when the engine is stopped through normal means such as a key is
used to turn off the engine.

> ｂ．太郎が車のエンジンを止まらせた。

This is used when the engine is stopped through abnormal means such as putting
sand or rocks in it. In other words, the engine is unable to be controlled
through normal means. When the causative intransitive is used, the engine is
seen as a not just an inanimate object, but as a thing that can act/move on
its own.

Thus, レンズをあちこちに巡らせる likely implies that the レンズ was moved around unnaturally
(i.e. it wasn't supposed to be moved in the first place or the ability to move
it was damaged/broken so some unusual methods had to be used to move it).




According to [this article](http://www.nkg.or.jp/wp/wp-
content/uploads/2018/04/113_causativeandtransitiveverbs.pdf), there are a few
main differences.

One difference is that if the thing that is being caused to do something is
inanimate, it can sound unnatural:

> ✖品物を並ばせる
>
> 〇品物を並べる
>
> ✖切手を集まらせる
>
> 〇切手を集める

The reason for this is that the causative construction implies a willingness
of the thing that is being caused to do something to do that action. So
because of this, in your example, レンズをあちこちに巡らす is probably the more natural
construction.

Another difference is that there is a difference in meaning:

乗客を降りさせる = `make the passenger get off the vehicle`

乗客を降ろす = `let the passenger get off the vehicle`

In the former, the driver or whoever causes the passenger to be motivated to
get off the vehicle. The latter is a routine thing in that the passenger is
just let get off.

_**Edit:**_

_Semantics of Japanese Causativization_ (1973) gives the following example for
the difference between the transitive and the causative intransitive when the
direct object is inanimate.

> ａ．太郎が車のエンジンを止めた。

This is used when the engine is stopped through normal means such as a key is
used to turn off the engine.

> ｂ．太郎が車のエンジンを止まらせた。

This is used when the engine is stopped through abnormal means such as putting
sand or rocks in it. In other words, the engine is unable to be controlled
through normal means. When the causative intransitive is used, the engine is
seen as a not just an inanimate object, but as a thing that can act/move on
its own.

Thus, レンズをあちこちに巡らせる likely implies that the レンズ was moved around unnaturally
(i.e. it wasn't supposed to be moved in the first place or the ability to move
it was damaged/broken so some unusual methods had to be used to move it).

