LEARN + JAPANESE / 63 of 186 JLPT N4
No Doubt About It に違いない
に違いない attaches to the plain form and means “there’s no mistaking it, it must be true.” It sits at the confident end of the certainty scale, built from 違う (to differ) plus ない, literally “there’s no way it’s different.”
に決まっている is a firm “of course / it’s bound to be,” often based on the speaker’s conviction. に相違ない is a formal written “there is no doubt that,” often used in careful arguments or reports. Both are strong; に違いない more often presents a reasoned inference, while に決まっている can sound more subjective or emphatic.
Yamamoto must have a lot of foreign friends.
Yamamoto must be used to moving houses.
Hint · 힌트
Ranked by confidence, かもしれない is the weakest, “might be,” だろう sits in the middle, “probably,” はず claims a reason-backed expectation, and に違いない tops them all, a near-certain conclusion drawn from strong evidence.
If it's right by the station, it must stay open late.
If they won an award recently, they must be getting featured in magazines and on TV a lot.
Hint · 힌트
な-adjectives and nouns attach directly with no だ, 元気に違いない, 田中さんに違いない, the same pattern as はず and のに. ありません politely softens ない at the end, in casual speech に違いない alone works fine.
Vocabulary
| Japanese | English |
|---|---|
| foreigner | |
| moving house | |
| to get used to | |
| TV program | |
| aimed at students | |
| private room | |
| to win an award | |
| magazine | |
| to introduce, feature | |
| from now on | |
| increasingly | |
| daycare | |
| population | |
| to decrease | |
| tax | |
| conviction, certainty | |
| evidence | |
| no room for doubt | |
| to conclude firmly | |
| obvious, clear |
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