Explanation
Expresses 'cannot help but...', 'will definitely...', or 'must do something'.
Formation
Verb-ない form (remove ない) + ずにはおかない
Detailed explanation
The ずにはおかない grammar point conveys the sentiment of an inevitable action or a strong emotional compulsion. It can mean 'I can’t let it pass without doing X' or 'I definitely will do X'.
Examples
Kare ga komatte iru to kiitara, tasukezuni wa okanai.
If I hear he is in trouble, I cannot help but assist him.
Shokuji no junbi ga kono mama da to, tetsudawazuni wa okanai darō.
If the meal prep stays like this, I won't be able to stop myself from helping.
Kono mondai ga kaiketsu shinai nara, kaizen-saku o kangaezuni wa okanai.
If this issue isn't resolved, I can't help but think of a solution.
Kanojo ga naite iru no o mitara, nagusamezuni wa okanai.
When I see her crying, I cannot help but comfort her.
Practice
Grammar content sourced from hanabira.org.