に相違ないThere can be no doubt
に相違ない presents a conclusion as unquestionably true. It expresses strong confidence in distinctly formal, often written language.
Making a weighty conclusion
Use this expression when evidence, circumstances, or reasoning leads you to a conclusion that you present with complete confidence. The form marks the writer's assurance; it does not by itself establish objective proof.
現場に残された痕跡から見て、何者かが裏口から侵入したに相違ない。
Judging from the traces left at the scene, there can be no doubt that someone entered through the back door.
AnalyzeThe traces provide grounds for the conclusion, while the ending presents that conclusion with strong formal certainty.
Put tense and negation before the expression
Past and negative meaning belong inside the clause that comes first. Keep the certainty expression itself unchanged; use the polite ending only when the surrounding style calls for it.
過去の記録を精査すれば、この制度は当初から十分に機能していなかったに相違ない。
A close examination of the past records leaves no doubt that this system had not functioned adequately from the outset.
AnalyzeBoth past and negative meaning appear before the target expression.
以上の状況から、交渉は難航するに相違ありません。
Given these circumstances, there can be no doubt that the negotiations will be difficult.
AnalyzeThe polite form remains highly formal rather than becoming conversational.
Three kinds of confident conclusion
に相違ない is the distinctly formal, weighty choice. に違いない expresses similarly strong conviction without the same marked formality. に決まっている is more conversational and often sounds emotionally insistent. はずだ instead emphasizes what is expected from a plan, fact, or other premise and need not express the same categorical assurance.
More examples
発見された文書は、計画の初期案に相違ない。
The discovered document must undoubtedly be an early draft of the plan.
Analyze現状を踏まえれば、追加の安全対策は必要に相違ない。
Given the present situation, there can be no doubt that additional safety measures are necessary.
Analyze複数の地域で同じ兆候が確認されており、影響は報告された数字より大きいに相違ない。
The same signs have been observed in several regions, so the impact is undoubtedly greater than the reported figures suggest.
Analyzeこれだけの証言が一致している以上、彼は事実を知っていたに相違ない。
Given that so much of the testimony agrees, there can be no doubt that he knew the facts.
Analyze長期的に見れば、この改革は社会全体に変化をもたらすに相違ありません。
In the long term, there can be no doubt that this reform will bring change to society as a whole.
Analyze