ことなしに

ことなしに is a formal expression meaning "without doing ~". It is used to indicate that something happens or is done without a particular action taking place. It attaches to the dictionary form of a verb.

This pattern is more literary and formal than the more common 〜～ないで or 〜～ずに, and it tends to appear in written language, speeches, and formal contexts. It often carries a nuance of criticism or surprise – implying that the omitted action should have been done, or that it is noteworthy that it was not done.

Comparison with ～ないで and ～ずに

All three expressions mean "without doing ~", but they differ in register and nuance:

• 〜～ないで: Casual and conversational. The most common in everyday speech.
• 〜～ずに: Slightly formal; used in both speech and writing.
• ことなしに: The most formal and literary. Often emphasizes that the omitted action was expected or important.

ことなしには

A closely related form is ことなしには, which adds the particle は to create a conditional or contrastive nuance, meaning "without doing ~, one cannot…" or "unless one does ~".