ひとりでに

Usage patterns

• 〈物もの〉がひとりでに〈動どう詞し〉for a thing to (do something) on its own, with no one touching it

  夜よ中なかに急きゅうにドアがひとりでに開ひらいた。

  In the middle of the night, the door suddenly opened by itself.

• 〈事こと〉がひとりでに治なおるfor something (like an injury or problem) to heal or resolve on its own

  小ちいさな傷きずはひとりでに治なおることが多おおい。

  Small cuts often heal on their own.