Without Doing — Formal (〜ずに)

〜ずに is the formal/literary equivalent of 〜ないで, meaning 'without doing.' It is more commonly found in written Japanese, formal speech, and set phrases.

Formation: change the verb to its ない-form, then replace ない with ず and add に. For example: 食べる → 食べない → 食べずに, 行く → 行かない → 行かずに. The important exception is する, which becomes せずに (not しずに).

While ないで and ずに are largely interchangeable in meaning, ずに sounds more formal and literary. It is preferred in written reports, news, and formal presentations. In casual conversation, ないで is more natural.