～に違いない（にちがいない）

About

The に違ちがいない pattern is used to make statements of certainty, and has the common translations: "There is no mistake that...", "X must be...", "There is no doubt that...", "Certainly...", or "Surely...".

～に違ちがいない makes subjective statements, based on the speaker's judgement, and has a written, formal tone.

The に違ちがいない pattern may attach directly to casual form verbs, い-adjectives, な-adjectives, and nouns.

E.g. 明日あしたは日曜日にちようびだから、混こむに違ちがいない。 "Tomorrow is Sunday so it will certainly be crowded."

E.g. 読よんでいる本ほんが面白おもしろいに違ちがいない。 "The book (they're) reading must be interesting."

E.g. プレッツェルを買かうのに並ならんでいるってことは、だいぶ暇ひまに違ちがいない。 "The fact that (they're) lined up to buy a pretzel must mean that they're quite free."

E.g. 何なにか隠かくしているみたいだから、あの人ひとが犯人はんにんに違ちがいない。 "They seem to be hiding something, so there's no doubt that that person is the culprit."

You may replace ない with 「ありません」to form the more polite 「に違ちがいありません」 pattern.

E.g. ここは水みずが綺麗きれいなので、作つくられるお酒さけも美味おいしいに違ちがいありません。 "The water here is clean, so the sake you can make (from it) must be delicious."

～に違ちがいない is commonly used in combination with the ～ということは pattern, as well as adverbs such as きっと.

E.g. 電話でんわに出でないということは、忙いそがしいに違ちがいないね。 "The fact that (they) aren't picking up the phone must mean that they're busy."

E.g. あんなに並ならんでいる店みせだから、きっとおいしいに違ちがいない。 "The store is that lined up so it must certainly be delicious."

Summary

• 

  The に違ちがいない pattern is used to make statements of certainty ("There is no mistake that...", "X must be...", "There is no doubt that...", "Certainly...", or "Surely...")

• 

  ～に違ちがいない makes subjective statements

• 

  ～に違ちがいない has a written, formal tone

• 

  The に違ちがいない pattern may attach directly to casual form verbs, い-adjectives, な-adjectives, and nouns