How does " ~ずにはいられない " work?


> 時代の流れを感じずにはいられない。 I can't help but feel time passing by.
>
> 彼のことを同情せずにはいられない。 I can't help but to feel sorry for him.
>
> 私は、彼の才能を賞賛せずにはいられない。 I can't help but admire his talent.

Would someone please explain in detail how "~ずにはいられない。" means "can't help
but"?

Is the いられない a form of いる？ If so, which one?

Or is it related to this: 「～し（せ）ざるをえない」?




`～ざるを得{え}ない` literally means "cannot not". `～ずにはいられない` literally means "cannot
be without (do)ing" as has been noted.

Both can be translated as "cannot help but..." in many cases. Both
`時代の流れを感じずにはいられない` and `時代の流れを感じざるを得ない` could work as "I cannot help but feel
the flow of time".

However, I found that `断念{だんねん}せざるを得ない` was used frequently, but
`断念{だんねん}せずにはいられない` was barely used. Asking someone about why this was,
apparently `～ずにはいられない` has connotations of doing something
compulsively/cravingly, and as a result that sentence sounds unnatural:

> × 希望を断念せずにはいられない "I cannot hold back the urge to abandon my hopes"
>
> △ 希望を断念せざるを得ない "I cannot help but abandon my hopes"

[According to
Daijisen](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E3%81%9A%E3%81%AB%E3%81%AF%E3%81%84%E3%82%89%E3%82%8C%E3%81%AA%E3%81%84&dtype=0&dname=0na&stype=0&pagenum=1&index=09980200),
`～ずにはいられない` expresses the feeling of being unable to hold back emotions or
hold back from performing actions even if one tries. Here are some examples
from [Space
ALC](http://eow.alc.co.jp/%E3%81%9A%E3%81%AB%E3%81%AF%E3%81%84%E3%82%89%E3%82%8C%E3%81%AA%E3%81%84/UTF-8/?pg=1)
which seem to show this:

> 盗{ぬす}みを働{はたら}かずにはいられない "Steal compulsively"
>
> どうしても～を食べずにはいられない "Have a compulsive urge for"
>
> 賭{か}け事{ごと}をせずにはいられないこと "Compulsive gambling"
>
> 浮気{うわき}をせずにはいられない "Can't help cheating" (compulsively cheat)




`～ざるを得{え}ない` literally means "cannot not". `～ずにはいられない` literally means "cannot
be without (do)ing" as has been noted.

Both can be translated as "cannot help but..." in many cases. Both
`時代の流れを感じずにはいられない` and `時代の流れを感じざるを得ない` could work as "I cannot help but feel
the flow of time".

However, I found that `断念{だんねん}せざるを得ない` was used frequently, but
`断念{だんねん}せずにはいられない` was barely used. Asking someone about why this was,
apparently `～ずにはいられない` has connotations of doing something
compulsively/cravingly, and as a result that sentence sounds unnatural:

> × 希望を断念せずにはいられない "I cannot hold back the urge to abandon my hopes"
>
> △ 希望を断念せざるを得ない "I cannot help but abandon my hopes"

[According to
Daijisen](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E3%81%9A%E3%81%AB%E3%81%AF%E3%81%84%E3%82%89%E3%82%8C%E3%81%AA%E3%81%84&dtype=0&dname=0na&stype=0&pagenum=1&index=09980200),
`～ずにはいられない` expresses the feeling of being unable to hold back emotions or
hold back from performing actions even if one tries. Here are some examples
from [Space
ALC](http://eow.alc.co.jp/%E3%81%9A%E3%81%AB%E3%81%AF%E3%81%84%E3%82%89%E3%82%8C%E3%81%AA%E3%81%84/UTF-8/?pg=1)
which seem to show this:

> 盗{ぬす}みを働{はたら}かずにはいられない "Steal compulsively"
>
> どうしても～を食べずにはいられない "Have a compulsive urge for"
>
> 賭{か}け事{ごと}をせずにはいられないこと "Compulsive gambling"
>
> 浮気{うわき}をせずにはいられない "Can't help cheating" (compulsively cheat)

