sensushi
← back to ないといけない

ないといけない details

write + not + must do

kakanai to ikenai

must do; have to do

meaning: have to write

明日あしたまでにレポートを出さださないといけない。

ashita made ni repooto o dasanai to ikenai.

I have to hand in the report by tomorrow. neutral

もう帰かえらないと。

mou kaeranai to.

I've gotta head home. casual

  • colloquial
  • contraction
  • past
  • polite

Examples

must do; have to — stating an obligation

明日あしたまでにレポートを出ださないといけない。

ashita made ni repooto o dasanaitoikenai.

I have to hand in the report by tomorrow. neutral

I'd better… — self-directed resolve with clipped sentence-final ないと, the consequence left unsaid

もう帰かえらないと。

mou kaeranai to.

I've gotta head home. casual

Formation

Variant notes

Notes

The と here is the conditional と — literally "if (you) don't do it, it won't do." Knowing that makes the sentence-final clipped form (行かないと。) feel natural rather than like a missing word.

Related patterns

Similar

  • なければならない

    なければならない reads stiffer and more written; ないといけない is the everyday spoken default.

  • なくてはいけない

    Same obligation, same いけない tail — ないと is the everyday spoken default, while なくては carries more weight and turns up more in writing and careful speech.

Opposite

  • なくてもいいnegated-obligation

    Negates the obligation itself — "you don't have to."

  • てはいけないprohibition

    Obligation applied to the negation instead — "you must not."

Lookalikes

  • ないで

    ないで is "without doing", not obligation — easy to misread at reading speed.

Same meaning

must do

PatternAttaches to
なければならない
なくてはいけない
ざるを得ない
wake-ni-wa-ikanai (planned)—