~なくする negative verb and する grammar


> 一人ぽっちでいられなくしたのはお前 (Spoken)

Is this just like the なくなる grammar (e.g. 食べなくなる) but with する implying it was
done by someone?




～くなる and [～くする](https://jlptsensei.com/learn-japanese-
grammar/%E3%81%84-adjective-%E3%81%8F%E3%81%99%E3%82%8B-ku-suru-meaning/) are
fundamentally different. For example:

  * 赤くなる  
to become red / to turn red

  * 赤くする  
to make (something) red

Likewise:

  * 一人ぽっちでいられなくなる  
to become unable to be alone

  * 一人ぽっちでいられなくする  
to make [someone] unable to be alone

And the original sentence is a [cleft
sentence](https://japanese.stackexchange.com/a/19208/5010) where お前 has been
pulled out for emphasis.

  * 一人ぽっちでいられなくしたのはお前(だ)。  
It's _you_ who made [someone] unable to be alone.  
(i.e., It's you who made [someone] prone to suffer from loneliness.)

Who this "someone" is depends on the context. It can be a third person, the
listener or the speaker themself. If this "someone" is the speaker, the
sentence roughly means something like "You made me unable to live alone
without you anymore."

