I have seen two example of this.

The first example come from "恋する星座" part 9 where the girl said a sentences with words "行かなきゃ"

The second example come from the song "Catch A Break" sung by Eguchi Takuya. The lyrics goes "買いに行かなきゃ"

Why does they use "-なきゃ" in said examples? Is it used only in daily conversation? What are the other example of words using "-なきゃ"?

[Sorry if I ask too much I'm really curious]


1 Answer 1


-なきゃ is a common casual contraction (amongst a few other variations) for the form -なければいけません, which literally means “it is no good if the action is not done”, aka. showing obligation that the action must be performed.

from your example:

  • 行かなきゃ: must go

  • 買いに行かなきゃ: must go to buy

FYI, here are some other variations and contractions of the structure


  • なければいけません

  • なくてはいけません

  • なければなりません

  • なくてはなりません

  • ないといけません


  • なきゃ(いけません)

  • なくちゃ(いけません)

  • なきゃ(なりません)

  • なくちゃ(なりません)

source: my experience and my Japanese class notes

  • 4
    Strictly speaking, なきゃ is a contraction of なければ, not なければいけません. As you pointed out, いけない does not necessarily follow なきゃ. For example, ~しなきゃだめ.
    – kandyman
    Mar 28, 2019 at 13:40

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