〜に相違ない ni sōi nai

〜に相違ない（ni sōi nai）means “there is no doubt that ...; must surely be ...”. A formal, written-style equivalent of 〜に違いない. Formation: V／Aい（普通形）＋ に相違ない ／ Aな・N（だ抜き）＋ に相違ない

there is no doubt that ...; must surely be ...

N2

Formation

V／Aい（普通形）＋ に相違ない ／ Aな・N（だ抜き）＋ に相違ない

Explanation

A formal, written-style equivalent of 〜に違いない. Expresses the speaker's strong conviction, based on reasoning, that something is certainly the case. Common in essays, reports and legal/official writing rather than casual speech.

Examples

この筆跡から見て、犯人は左利きに相違ない。
このひっせきからみて、はんにんはひだりききにそういない。
Judging from this handwriting, the culprit is without doubt left-handed.
彼が一晩で書き上げたに相違ない。
かれがひとばんでかきあげたにそういない。
He must surely have finished writing it in one night.

Note

Meaning is identical to 〜に違いない but the tone is stiffer and more written. With na-adjectives and nouns, attach directly without だ (静か＋に相違ない).

FAQ

〜に相違ない — what does it mean and how is it used?

there is no doubt that ...; must surely be .... A formal, written-style equivalent of 〜に違いない. Expresses the speaker's strong conviction, based on reasoning, that something is certainly the case. Common in essays, reports and legal/official writing rather than casual speech.

〜に相違ない — how do you form it?

V／Aい（普通形）＋ に相違ない ／ Aな・N（だ抜き）＋ に相違ない

〜に相違ない — any usage notes?

Meaning is identical to 〜に違いない but the tone is stiffer and more written. With na-adjectives and nouns, attach directly without だ (静か＋に相違ない).

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