Grammar Info

N4 Lesson 9: 8/16


Must do, Have to do

Verb[ない]+と+いけない/ならない is also used to express duty or necessity.


Verb[ない] + ければ + いけない
Verb[ない] + きゃ + いけない


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About なければいけない

Like なくてはいけない, なければいけない is a structure that implies that something 'must be done'. However, it is important to remember that this is actually a double negative, and therefore means 'If (A) is not done, it cannot go', or more simply '(A) cannot not be done'.
To make this construction, the auxiliary verb ない will need to be conjugated with , creating なければ (if not). After this, いけない (to not be able to go) will be added to the end.
  • 来月(らいげつ)友達(ともだち)結婚式(けっこんしき)()なければいけない
    Next month, I have to go to my friend's wedding. (Not going to the wedding is not going to work)
  • (くるま)駐車場(ちゅうしゃじょう)()なければいけない
    Cars have to be parked in parking lots. (Not being parked in a parking lot is unacceptable)
As learned in the なきゃ lesson, なければ may be shortened to なきゃ. This structure is frequently used either with or without the added いけない.
  • ここ(はな)ている場合(ばあい)じゃない息子(むすこ)(むか)えに()なきゃ
    This is not the time to talk here, I have to go pick up my son.
  • 宿題(しゅくだい)調(しら)なきゃいけない(こと)があるから、パソコン()
    Since I need to look up something for my homework, would you please lend me your computer?
While いけない (to not be able to go) and ならない (to not become) are quite similar, ならない will rarely be used outside of formal situations, or in writing. Due to this, いけない will be heard much more frequently in speech (when it is not omitted).



  • 仕事(しごと)()なければいけない

    I have to go to work.

    • (ふゆ)になったら暖房(だんぼう)つけなければいけません

      When winter comes, I will have to turn on the heater.

      • (おぼ)えにくいけど(おぼ)なければいけません

        It is difficult to remember, but I must (remember).

        • (あに)みたいに大学(だいがく)()なければいけない()われました

          I was told that I have to go to college like my older brother.

          • (あたま)(いた)すぎて(くすり)()なければいけない

            My head hurts so much that I must take medicine.

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            なければいけない – Grammar Discussion

            Most Recent Replies (13 in total)

            • 5quirrel


              If it’s an interchangeable expression with なくてはいけない is there a trick to knowing which the review is asking for?

              Or am I missing something?

            • Eodis


              I’m not sure i perfectly understand the following example :

              Children will try all sorts of things, so you must always keep watch.

              Why is 見る first turned in the ている form here, which of the following grammar point is it ?

            • Pablunpro



              It would be the first one, as you must keep watch, so you have to watch and keep on watching (existing in a constant state of ‘doing’ the watching) so that the kids don’t burn down the house.


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