Why is こと used at the end of this kind of sentences?


So, often I see こと being used at the end of sentences like

> 「私の最後の希望はあなたと共に死ねることなのに」

> 「それは僕の生命を吸い取るために 僕の全身を凍らせていないことだ」

Is this like how in English you normally would say "My aim is ーーー" and you
would use a verb in gerund form like "living there" (although to live there
would be ok too)? So because 希望 is a noun what 希望 is should be a noun too,
therefore 「死ねること」is like "My hope is _dying_ with you", right?

Should the second phrase be understood as:

> それは•••全身を凍らせていないことだ  
>  That is... not _freezing_ my whole body

Would this phrases make sense without こと?




Your understanding is basically correct, this こと is a nominalizer, something
that turns a verb into a noun. You need a noun before だ, なのに, etc.

  * [What is the difference between the nominalizers こと and の?](https://japanese.stackexchange.com/q/1395/5010)
  * Wasabi - [Nominalizers: こと and の](https://www.wasabi-jpn.com/japanese-grammar/nominalizers-koto-and-no/)

But note that 死ねる is the potential form of 死ぬ. Thus 死ぬこと is "dying" but 死ねること
is "being able to die". Likewise, 凍らせていない is negative -teiru form. 凍らせないこと is
"not freezing" but 凍らせていないこと is "having not frozen".

> 私の最後の希望はあなたと共に死ねることなのに  
>  My last hope is being able to die with you, but...
>
> それは僕の生命を吸い取るために 僕の全身を凍らせていないことだ  
>  It is that [something/someone] has not frozen my whole body in order to
> absorb my life.

