If something is impromptu, you do it or say it with no plan written down and no practice beforehand. An impromptu speech is one you give because someone suddenly asks you. An impromptu visit is one you did not arrange.

If something is impromptu如果某件事是即興的, you你 do it or say it with no plan written down and no practice beforehand做這件事或說這句話的時候，事先沒有寫好計畫，也沒有練習過。An impromptu speechimpromptu speech is one you give because someone suddenly asks you是因為有人突然要求你，你才臨時發表的演講。An impromptu visitimpromptu visit is one you did not arrange則是你沒有事先安排的拜訪。

The word usually sits in front of a noun, but you can also say they spoke impromptu. It feels a little educated and neat; it is not slang.

The word這個字 usually sits in front of a noun通常放在名詞前面, but但 you can also say they spoke impromptu你也可以說「they spoke impromptu」。It它 feels a little educated and neat給人的感覺有點文雅、講究; it它 is not slang不是俚語。

Though actually, 'no preparation' is tidier than real life: an impromptu talk still uses words and stories you already have — you just did not sit down to write them. For comedy and drama on a stage, younger people often say the shorter word improv instead.

Though actually不過其實 'no preparation' is tidier than real life「完全沒準備」這種說法比現實乾淨一點: an impromptu talk一場impromptu talk still uses words and stories you already have用的還是你原本就有的字彙和故事 — you你 just did not sit down to write them只是沒有坐下來把它們寫出來而已。For comedy and drama on a stage在舞台上的喜劇和戲劇表演裡, younger people年輕人 often say the shorter word improv instead常常會改用比較短的字improv。