Grammar Info

N5 Lesson 9: 9/13

なくてはならない

Must do, Have to do

Also used to express duty or necessity. Click here if you are curious about なくて conjugation

Structure

Verb［ない］+ なくては + ならない
Verb［ない］+ なくちゃ + ならない

Details

  • Part of Speech

    Expression

  • Word Type

    Auxiliary Verb

  • Register

    Formal

  • 品詞

    表現

  • 単語の種類

    助動詞

  • 使用域

    硬い

About なくてはならない

Much like てはならない, なくてはならない states that something 'must not' be done. However, this is where the similarities end. なくてはならない is an example of a double negative in Japanese, and actually has the meaning '(A) must be done', or 'must do (A)'.

While this grammar point is usually translated as 'must do', the literal translation is 'must not, not do (A)'. This double 'not' is where many learners have difficulties. ならない simply means 'cannot become', and comes from the negative form of なる.

To use this structure, simply create the negative form of a verb, and then convert ない to なく (the conjunctive form of an い-Adjective), followed by て. After this, は is added, and then finally ならない.

ならない is considered to be the most formal structure out of ならない, いけない, and だめ. It is regularly used in formal writing, or semi-formal/formal speech. いけない (the most common variation) and だめ (the most casual variation) are also acceptable in many situations.

Caution

The ては in なくては is often shortened to ちゃ, as this is easier to say. なくちゃ may then be followed by ならない. However, due to ならない being quite formal, なくちゃ (a casual structure) will not be used with ならない on a regular basis. It is more common to see なくちゃ paired with いけない, or だめ.

  • 今日(きょう)は沢山(たくさん)走(はし)ったからシャワーを浴(あ)びなくちゃならない。
    Because I ran a lot today, I must take a shower.
  • バーベキューに肉(にく)を持(も)って行(い)かなくちゃいけない。
    I gotta bring meat to the barbeque.
  • 冬(ふゆ)になる前(まえ)にキャンプに行(い)かなくちゃだめだね。
    We gotta go camping before it becomes winter, right?

These casual structures are very similar to words like 'gotta' in English.

Examples

  • 毎日(まいにち)勉強(べんきょう)をしなくてはならない。

    You must do your studies every day.

  • ３時(じ)半(はん)までに、銀行(ぎんこう)に行(い)かなくてはならない。

    By 3:30, I have to go to the bank.

  • もう二(に)時(じ)ですか！まだお弁当(べんとう)食(た)べてないです。食(た)べなくてはならない。

    It's already two?! I haven't eaten my bento yet. I have to eat.

  • 京都(きょうと)で電車(でんしゃ)を降(お)りなくてはならない。

    I must get off the train in Kyoto.

  • 君(きみ)が決(き)めなくてはならないよ。

    You have to decide.

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なくてはならない – Grammar Discussion

Most Recent Replies (26 in total)

  • IcyIceBear

    IcyIceBear

    Because that review is only testing ならない. They’re synonyms tested as two separate points. いけない doesn’t work only because it wants ならない specifically. Real world application they’re mostly interchangable

  • Meatdog

    Meatdog

    Man this is the second question of mine you have answered, you are on fire! haha thanks again!

  • tangerine

    tangerine

    死ぬ前に汽車に一度は＿。（乗る）

    I don’t know if my settings changed or if the site changed but all I got as a clue for this one was “Negative non-past, Standard”, which seems a lot less helpful than the “long form / casual / て＋なる” I see earlier in this thread.

    Is there something about the prompt that makes なくてはならない clear without cycling through all of the other permutations of "must"s out there? There are no alts for this one.

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