1.
in the blink of an eye, in no time, before you know it
An expression describing something happening extremely quickly, so fast that one can only say "ah!" Literally: the interval of saying "ah."
あっという間に終わった。
It was over in the blink of an eye.
休みはあっという間に過ぎた。
The vacation was over before I knew it.
久しぶりに友達と話していたら、時間があっという間に過ぎた。
I was chatting with a friend I hadn't seen in a while, and time flew by in no time.
あっという間 literally means "the space/interval of saying 'ah!'" — so brief you barely have time to exclaim.
COMMON PATTERNS:
- あっという間に + verb (in no time, ~): あっという間に終わった (It was over in a flash)
- あっという間だった (it went by in no time)
- あっという間の + noun (fleeting ~): あっという間の出来事 (a fleeting event)
USAGE:
Nearly always used with the particle に. Very common in everyday conversation and writing. Often expresses surprise at how quickly time has passed or an event occurred. Used for both positive and neutral situations (a fun time passing quickly, an event ending suddenly).
SIMILAR EXPRESSIONS:
- 一瞬で: in an instant (slightly more formal)
- 瞬く間に: in the blink of an eye (literary)
- すぐに: immediately, right away (neutral, no surprise nuance)