Compared to the "naide" form, this one is used with a more negative connection to the thing you didn't do (as you would regret that you didn't do something).
例)
昨日学校へ行かず、ゲームセンターで遊んでしまった。
maki
Seems to be more official than plain ~[なくて] form. AFAIK, it's quite often used in writing.
mathrick
[Vn-zu] seems to be the same article, except with more examples and so on, and placed in the level 2 entries...
Shadowstar
you can also shorten 〜ずに into 〜ず.
誠
聞き返すことも忘れずに! Don't forget to ask in return. (Example: "How are you?" "Fine, thanks. And you?") This is from a Japanese English teacher's lesson.
Watari
〜ずに is the shortened form of 〜ないで
K
Isnt 〜ずに A more formal form, not a contraction?
shiho-chan
I think ず is a classical form of ない that still comes up, as in 知らず. 〜ずに means 〜ないで, and is used mostly in writting, although I heard it spoken sometimes.
sw
It may of interest to note that in some dialect, 行かず would mean 行こう(let's go).
bamboo4
行かず maybe 行きませんか so sw are right,ず 〜= ない
ngonhan2k7
how do you say the negative version of 食べず is it 食べずじゃない? just for the purpose of saying something like, i didn't come to school without eating. 学校に食べずじゃないで来た.or would you just neg kuru? like, 学校を食べずに来なかった.
nellyaudrey
To nellyaudrey You can' t do a negative of a negative form in Japanese. You'll only be mishunderstood. The Japanese are more simple minded. The negative of a negative is positive, so say it positive! 朝ご飯食べて学校に来ました。I came to school having eaten breakfast. Anyway, if you want to say your negative-negative sentence at any cost the closer sentence you can use is a negation of the all positive sentence. 朝ご飯食べずに学校に来ましたと違います.It's not true that I came to school without eating breakfast.