Translation guide
In Japanese, expressing 'an instant' depends on whether you mean a very short moment in time, doing something immediately, or something happening in the blink of an eye. The most common and versatile word is 瞬間 (shunkan). Other expressions add nuance like brevity, suddenness, or literary flavor.
Referring to a brief point or duration, often used in phrases like 'in an instant' or 'for an instant'.
The most common and neutral word for 'instant' or 'moment'. Can be used in both spoken and written Japanese.
その瞬間、すべてが変わった。
In that instant, everything changed.
一瞬の出来事だった。
It happened in an instant.
Literally 'one instant', emphasizing the brevity. Very common in everyday speech.
一瞬、何が起きたかわからなかった。
For an instant, I didn't know what had happened.
A Buddhist term for an extremely short instant, used in poetic or dramatic contexts. Less common in daily conversation.
刹那の輝きだった。
It was a momentary brilliance.
Expressing that something happens right away, at once, or in no time.
The most common way to say 'immediately' or 'right away'. Natural in both casual and polite speech.
すぐに戻ります。
I'll be back in an instant.
Means 'instantly' or 'on the spot', often used in formal or written contexts.
彼は即座に返事をした。
He replied in an instant.
Literally 'in the time it takes to say ah', meaning 'in the blink of an eye' or 'before you know it'. Very colloquial.
あっという間に終わった。
It was over in an instant.
Describing something that happens so fast it's almost imperceptible.
Literally 'in the time it takes to blink', a common and slightly literary expression for 'in an instant'.
瞬く間に消えた。
It vanished in an instant.
A dramatic, literary phrase meaning 'with speed that the eye cannot follow'. Used in storytelling.
目にも止まらぬ速さで走り去った。
He dashed away in an instant.
瞬間 (shunkan) is a noun meaning 'moment' or 'instant', while 一瞬 (isshun) is often used adverbially to mean 'for an instant'. 一瞬 is more common in casual speech for 'a split second'.
その瞬間、彼は笑った。
At that instant, he smiled.
一瞬、彼は笑った。
For an instant, he smiled.
刹那 (setsuna) is a very literary or dramatic word. Using it in everyday conversation can sound overly poetic or strange. Stick to 瞬間 or 一瞬 for normal situations.