Translation guide
How to express that an action or result happened without intent, by accident, or inadvertently. Japanese offers several adverbs and expressions that differ in nuance, formality, and whether the outcome is positive, negative, or neutral.
The action happened because the person was not paying attention or acted on impulse, not because they planned it.
Used when you do something you know you shouldn't, or something habitual, almost automatically. Often implies a slight lack of self-control.
つい食べ過ぎてしまった。
I unintentionally ate too much.
I accidentally let the secret slip.
Used when you make a careless mistake because you weren't paying attention. Often for forgetting, overlooking, or doing something absentmindedly.
I unintentionally forgot the appointment.
I accidentally missed my stop.
Used when you react spontaneously, without thinking, often due to surprise or strong emotion. The action is reflexive.
I unintentionally laughed.
I unintentionally screamed.
Used when something happens gradually without you realizing it. Often for changes in state or accumulated actions.
I had unintentionally fallen asleep.
The outcome was not intended; it happened due to chance or a mistake, often with a negative result.
Means 'by chance' or 'accidentally'. Neutral; can be used for both positive and negative coincidences.
I met him unintentionally.
Means 'by mistake' or 'erroneously'. Used when you do something wrong unintentionally, often in formal or written contexts.
I unintentionally deleted the file.
Similar to 誤って but more casual. Used when you do something by mistake, like taking the wrong thing or pressing the wrong button.
I unintentionally pressed the wrong button.
The person did not have the intention to cause a particular result; it was not deliberate.
Pattern meaning 'I didn't intend to ~'. Used to deny intent. Attach to the dictionary form of a verb.
I didn't mean to hurt you.
Casual phrase meaning 'it wasn't on purpose'. Used to deny intentionality in everyday speech.
It wasn't intentional.
Formal phrase meaning 'not deliberate'. Used in official statements or legal contexts.
That was unintentional.
The action or reaction happened automatically, beyond the person's control, often due to a physical or emotional response.
つい is for giving in to temptation or habit (e.g., eating too much). うっかり is for careless mistakes (e.g., forgetting something). 思わず is for spontaneous, emotional reactions (e.g., laughing out loud).
I unintentionally ate the sweets (couldn't resist).
I accidentally dropped the sweets (wasn't paying attention).
I unintentionally grabbed the sweets (reflexively).
わざとじゃない is very casual and can sound childish or defensive. For formal apologies, use 故意ではありません or 〜つもりはありませんでした.
I unintentionally offended him.
She unintentionally revealed the secret.
My hand moved unintentionally.