ずにwithout doing
"Without doing." It means what ないで means and is a little stiffer: more common in writing, but people say it too.
She left the room without saying anything.
I went to the restaurant without booking, and it was full.
How to form it
Verb ない-form: ない → ずに する → せずに
行かない → 行かずに, 食べない → 食べずに, 来ない → 来ずに. する is the one irregular: せずに, never しずに. This verb and the main verb are about the same person.
ずに or ないで?
I fell asleep without locking the door.
What you'd say to a friend.
I fell asleep without locking the door.
The same thing, a little stiffer. At home in writing, and said as well.
ずに only takes the place of this ないで, the one that means "without doing". A request keeps ないで.
Not said: ここで
(Please don't take photos here.)
撮らないでください.
Where you'll meet it
In novels, news, manuals and notices it is the usual way to say "without doing".
I ran the machine without reading the instructions.
You cannot enter the building without ID.
In conversation you will hear it most in a few everyday phrases, often when someone is asking you to do something:
忘れずにbe sure to, don't forget to
Don't forget to bring an umbrella tomorrow.
遠慮せずにfeel free to
If there's anything you don't understand, feel free to ask.
気にせずにdon't mind, never mind
Don't mind me. Go on ahead.
Without the に
The に often drops, mostly in writing and in set pairs like 休まず働く. It still means "without doing".
He solved the problem himself, without relying on anyone.
I worked straight through, even on my days off.
In writing, ず alone is also a plain "didn't, and" between two halves of a sentence. They don't have to be about the same thing.
It didn't rain, and the wind was light too.
Longer forms built on ずに
Close neighbours
て・ないでN4
The everyday partner, and the one that makes requests: 行かないで, 撮らないでください.
I drink coffee without sugar.
Stiffer again, for formal writing and speeches.
He worked for thirty years without once taking time off.
確認し、報告したN3
In writing, a positive verb joins with its bare stem, the way a negative one joins with ず.
The research team gathered the materials and organized them by period.
Check yourself
1"I went to bed without doing my homework."
宿題を
Choose an answer to see why.
2A notice in a museum: "Please do not touch."
Choose an answer to see why.
More detail
Some everyday adverbs are old ず forms: 思わず (without meaning to), 相変わらず (as ever), とりあえず (for now).
More sentences
I went to school without eating breakfast.
He signed the contract without checking it.
The person in charge didn't come to the meeting and just sent the materials.
来ずに: read こ, as in 来ない.
I couldn't get to sleep last night, so I read until morning.
With "couldn't", it shades into "and so".
The athletes kept running to the end without a single break.