Translation guide
The English word "motive" refers to the reason or driving force behind an action. In Japanese, the most common equivalent is 動機 (どうき), but depending on context, other words like 目的 (もくてき) or 理由 (りゆう) may be more natural. This guide helps you choose the right expression.
Expressing the underlying reason or incentive for doing something, especially in neutral or formal contexts.
The most direct translation for 'motive', used in both everyday and formal situations. Often appears in phrases like 動機がある (have a motive) or 動機を尋ねる (ask about someone's motive).
彼の行動の動機は何ですか。
What is his motive for acting that way?
犯行の動機はまだわかっていない。
The motive for the crime is still unknown.
Means 'reason'. More general than 動機 and can be used in casual conversation. It doesn't carry the same psychological nuance as 'motive' but is often sufficient.
遅刻の理由を教えてください。
Please tell me the reason for your lateness.
Means 'purpose' or 'objective'. Use when the motive is goal-oriented. Often interchangeable with 動機 when the reason is tied to an intended outcome.
彼の留学の目的は何ですか。
What is his motive for studying abroad?
Referring to a secret or selfish reason behind someone's actions, often with a negative connotation.
Literally 'under-heart', meaning a hidden agenda or ulterior motive. Often used when someone's kindness or offer seems suspicious.
彼の親切には下心があると思う。
I think there's an ulterior motive behind his kindness.
Literally 'back purpose', meaning a hidden objective. More direct than 下心 and can be used in both casual and formal settings.
彼の提案には裏の目的がありそうだ。
His proposal seems to have a hidden motive.
A somewhat old-fashioned or literary term for a secret scheme or motive. Often used in detective stories or dramatic contexts.
Specifically referring to the motive behind a crime, often used in police investigations or news reports.
The standard term in legal and news contexts. Often combined with 犯行 (crime) as 犯行動機.
警察は犯行動機を調べている。
The police are investigating the motive for the crime.
A more general way to say 'reason for the crime'. Less formal than 動機 but still common in news.
犯行の理由は金銭トラブルだった。
The motive for the crime was a financial dispute.
Expressing that there is no reason or incentive to do something, often in defensive or explanatory situations.
Directly means 'have no motive'. Can be used in both casual and formal contexts.
私には彼を騙す動機がない。
I have no motive to deceive him.
Means 'have no reason'. More casual and broader than 動機がない.
彼が嘘をつく理由がない。
There's no motive for him to lie.
動機 (motive) emphasizes the psychological drive behind an action, often used in serious contexts like crime or important decisions. 理由 (reason) is a general, everyday word for any cause or explanation. 目的 (purpose) focuses on the goal or intended outcome. Choose based on nuance: if you want to sound analytical, use 動機; if casual, 理由; if goal-oriented, 目的.
While 動機 is the direct translation, it can sound overly formal or psychological in everyday conversation. For simple questions like 'Why did you come?', use 理由 or 目的 instead.
彼女の真意がわからない。
I don't understand her motives.
真意 (true intention) is often more natural than 動機 when expressing confusion about someone's real reasons.
彼の魂胆を見抜いた。
I saw through his ulterior motive.