JapaneseJLPT
JLPT N3 grammar · Chapter 1

～てからでないと・～てからでなければ

Something cannot happen until another step is finished

You’ll be able to say that one action is a necessary prerequisite before another can happen.

Illustration of the scene described by You cannot enter the mountain trail until you put your shoes on properly.
Read it first

靴くつをしっかり履はいてからでないと、山やまへ入はいれませんよ。

kutsu o shikkari haite kara denaito, yama e hairemasen yo.

What do you think this sentence means?

You cannot enter the mountain trail until you put your shoes on properly.

Why it means that

One thing must happen first

～てからでないと says that the main-clause action is impossible until the first action is completed. It is often used with a negative potential or another expression of inability. ～てからでなければ is a more formal equivalent.

Examples

宿題しゅくだいをしてからでないと、テレビを見みてはいけません。

shukudai o shite kara denaito, terebi o mite wa ikemasen.

You cannot watch TV until you have done your homework.

父ちちに聞きいてからでないと、返事へんじができません。

chichi ni kiite kara denaito, henji ga dekimasen.

I cannot give you an answer until I have asked my father.

How it is built

Put the required action first

Attach からでないと (or からでなければ) to the て-form of the prerequisite. The result after it is normally negative: ～できない, ～わからない, or ～無理むりだ. Do not use it simply for two actions in sequence; it emphasizes that the first one is required.

Verb て-form+からでないと+negative resultVerb て-form+からでなければ+negative result
Examples

実際じっさいに使つかってからでないと、便利べんりかどうかわかりません。

jissai ni tsukatte kara denaito, benri ka dou ka wakarimasen.

You cannot know whether it is useful until you actually use it.

予約よやくしてからでなければ、この部屋へやは利用りようできません。

yoyaku shite kara denakereba, kono heya wa riyou dekimasen.

This room cannot be used unless you reserve it first.

Compare

～てから vs ～てからでないと

～てから only puts two actions in order. ～てからでないと makes the first action a requirement, so the part after it says what cannot happen yet.

  • ～てから, after

    手てを洗あらってから、食たべます。

    te o aratte kara, tabemasu.

    I will eat after I wash my hands.

    Just gives the order of two actions.

  • ～てからでないと, not until

    手てを洗あらってからでないと、食たべられません。

    te o aratte kara denaito, taberaremasen.

    I cannot eat until I have washed my hands.

    Makes washing a condition, and the result after it is negative.

Examples

医者いしゃに相談そうだんしてからでないと、この薬くすりは飲のめません。

isha ni soudan shite kara de nai to, kono kusuri wa nomemasen.

You cannot take this medicine until you have consulted a doctor.

料金りょうきんを払はらってからでなければ、鍵かぎはお渡わたしできません。

ryoukin o haratte kara de nakereba, kagi wa owatashi dekimasen.

We cannot hand over the key until you have paid the fee.

眼鏡めがねをかけてからでないと、この小ちいさい字じは読よめない。

megane o kakete kara de nai to, kono chiisai ji wa yomenai.

I cannot read these small letters until I put on my glasses.

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