ないことにはunless … first; can't … without
A first step hasn't been taken yet, and until it is, you can't tell, can't decide or can't begin. English says "unless … first", "not until" or "can't … without".
I can't judge the color without seeing the real thing.
You can't tell what someone is like unless you meet them.
How to form it
Verb in the ない-form + ことには + what can't be known or done
見ない → 見ないことには. Very often on てみる, to try: やってみないことには.
- Before it
- The step that hasn't happened yet: 見ない, 聞いてみない, そろわない.
- After it
- Something that can't be known or done until then: 分からない, 決められない, 無理だ.
- How it sounds
- Firm, not stiff: said and written alike. It often argues for getting on with that first step, or explains why there is no answer yet.
The ones you'll hear
やってみないことにはuntil you try
You won't know whether it works until you try.
ないことには何とも言えないcan't say until …
I can't say anything until I see the test results.
ないことには始まらないnothing can start until …
In any case, nothing can start until we get the people together.
In use
We can't decide how to respond until we've looked into the situation properly.
We can't reach a conclusion until we have all the data we need.
There's no way service can resume until we know it's safe.
No ない at the end, but 無理だ does the same job.
Not every "unless"
English "unless" can end in a plan that goes ahead: "I'll walk unless it rains". ないことには can't. That "unless" is なければ.
Not said: 雨が
(I'll walk unless it rains.)
雨が降らなければ、歩いて行きます.
Close neighbours
なければN4
Any "if not", whatever follows: a plan, a request, a "can't". Before a "can't" it says the same thing, with less of the feeling of being stuck. There, conversation usually has ないと.
If you don't understand, please ask.
ない限りN2
"Unless" too, but about how long something holds: a rule, a policy, a firm no. Its ending can be a plain "will".
Unless circumstances change, we will stick to this policy.
てからでないとN3
The order is the point: one thing has to be finished before the other, as in rules and instructions.
You can't take this medicine until you have eaten.
Check yourself
1"Unless the trains are late, I'll be there by eight."
電車が
Choose an answer to see why.
2What does this mean?
住んで
Choose an answer to see why.
More detail
An adjective or a noun can come before it too, far less often:
Without a big enough budget, it will be hard to get the staff we need.
In conversation the ending is often left hanging: まず本人に聞いてみないことには….
More sentences
I won't know whether I can walk in these shoes for hours until I actually try them on.
You won't know what they think until you've at least talked to them.
I can't judge whether the repair bill is fair without seeing the site for myself.