Translation guide
Describes something that does not stay the same in quality, behavior, or logic. Japanese expressions vary depending on whether you mean contradictory, variable, or unreliable.
When statements, ideas, or actions conflict with each other or with previous ones.
The most direct and common way to say something is logically inconsistent or contradictory. Often used for statements, arguments, or actions that don't align.
彼の説明は矛盾している。
His explanation is inconsistent.
その政策は矛盾している。
That policy is inconsistent.
Literally 'lacks consistency'. Used for behavior, quality, or performance that is not uniform over time.
彼の行動には一貫性がない。
His behavior is inconsistent.
Means 'doesn't add up' or 'incoherent'. Used when a story, alibi, or logic has gaps or contradictions.
彼の話はつじつまが合わない。
His story is inconsistent.
When something is not stable or reliable in its level, such as work quality, sports performance, or product standards.
Means 'unstable' or 'not steady'. Commonly used for performance, quality, or conditions that fluctuate.
彼の成績は安定しない。
His grades are inconsistent.
このレストランの味は安定しない。
The taste at this restaurant is inconsistent.
Colloquial expression meaning 'uneven' or 'patchy'. Often used for skills, effort, or quality that varies from time to time.
彼のプレーにはムラがある。
His play is inconsistent.
Means 'there is variation' or 'scatter'. Used for data, measurements, or product quality that is not uniform.
製品の品質にばらつきがある。
There is inconsistency in product quality.
When a person or system does not follow through consistently, such as being late, changing rules, or failing to meet expectations.
Means 'unreliable' or 'cannot be counted on'. Used for people, information, or things that are not dependable.
彼は当てにならない。
He is inconsistent (unreliable).
Colloquial phrase meaning 'what someone says changes constantly'. Implies inconsistency in statements or decisions.
上司は言うことがコロコロ変わる。
My boss is inconsistent in what he says.
矛盾している implies a direct contradiction between two things (A and not A). 一貫性がない means lack of uniformity over time or across instances, without necessarily a logical contradiction.
彼の主張は矛盾している。
His argument is contradictory.
彼の主張には一貫性がない。
His arguments are inconsistent (vary from time to time).
The English word 'inconsistent' covers many nuances. Direct translations like 不一致 (ふいっち) are rarely used in natural Japanese. Choose the expression that matches the specific meaning.