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JLPT N3Hearsay & Conjecture

～に違いない— There's No Doubt

Expresses the speaker's strong conviction: 'it must be ~ / there's no doubt that ~'. It states a confident conclusion drawn from evidence or reasoning, stronger than はず or だろう. The speaker is almost certain, though not stating a proven fact.

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Pro lessonUNIT 71 · HEARSAY & CONJECTURE

Structure · 形

[Plain form (na-adj/noun drop だ)] + に違いない

Examples · 例文

  • 電気が消えているから、彼はもう寝たに違いない。

    Denki ga kiete iru kara, kare wa mou neta ni chigainai.

    The lights are off, so he must have already gone to sleep.

    Confident conclusion from evidence (lights off) + に違いない

  • この味は本場の料理に違いない。

    Kono aji wa honba no ryouri ni chigainai.

    This taste must be authentic local cuisine.

    Noun 料理 attaches directly (no だ) + に違いない

  • あんなに勉強したのだから、合格するに違いない。

    Anna ni benkyou shita no da kara, goukaku suru ni chigainai.

    Since he studied that much, he'll surely pass.

    Verb 合格する + に違いない for a strong prediction

Usage notes · 注意

  • Expresses the speaker's own strong conviction, not objective proof.
  • Noun/na-adjective attach directly (drop だ): 学生に違いない.
  • More emphatic and formal than だろう / でしょう.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones ～に違いない is tested against.

vsはずだ

はずだ is a logical expectation based on known facts/rules; に違いない is the speaker's subjective strong conviction and feels more emotionally certain.

vsだろう

だろう is a soft guess ('probably'); に違いない expresses near-certainty and is much stronger.

More hearsay & conjecture

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