How to break down who did what in AにBをCさせる


I'm trying to understand the following:

> 後輩にサイフを開かせることはないよ

I guess this could be generalized as AにBをCさせる.

It's confusing. Maybe if someone can break down how to understand this and
then I can memorize it.




Usually, you have a sentence like:

> 後輩がサイフを開く  
>  koohai ga saihu wo hirak-u  
>  'the junior opens the wallet'

where the subject takes `が` and the object takes `を`.

There is a morpheme `-(s)ase-` 'let', 'make' that expresses causative. The way
you use it is that you embed the sentence, and change the embedded subject `が`
into `に`, take another subject that will be the causer.

> 君が後輩にサイフを開かせる  
>  kimi ga [koohai **ni** saihu wo hirak]-ase-ru  
>  'you let [the junior open the wallet]'

In your example, the subject `君が` is actually omitted, so you have

> 後輩にサイフを開かせる




Usually, you have a sentence like:

> 後輩がサイフを開く  
>  koohai ga saihu wo hirak-u  
>  'the junior opens the wallet'

where the subject takes `が` and the object takes `を`.

There is a morpheme `-(s)ase-` 'let', 'make' that expresses causative. The way
you use it is that you embed the sentence, and change the embedded subject `が`
into `に`, take another subject that will be the causer.

> 君が後輩にサイフを開かせる  
>  kimi ga [koohai **ni** saihu wo hirak]-ase-ru  
>  'you let [the junior open the wallet]'

In your example, the subject `君が` is actually omitted, so you have

> 後輩にサイフを開かせる

