A prerequisite is something you must have or do before something else can happen.

A prerequisite is somethingprerequisite 指的是某件事，you must have or do你必須先擁有或先做到，before something else can happen另一件事才能發生。

Schools love it: Calculus is a prerequisite for Physics 2 — you cannot take the second class until you have passed the first. Jobs use it too: three years’ experience as a prerequisite. As an adjective: a prerequisite skill, a prerequisite course.

Schools love it學校很愛用這個字：Calculus is a prerequisite for Physics 2像 Calculus is a prerequisite for Physics 2（微積分是物理2的先修課）——you cannot take the second class你不能去修後面那堂課，until you have passed the first除非你先通過前一堂。 Jobs use it too工作徵才也會用，three years' experience as a prerequisite像「三年工作經驗」就常被列為先決條件。 As an adjective當形容詞用時，a prerequisite skill, a prerequisite course就是 a prerequisite skill（必備技能）、a prerequisite course（先修課程）。

It is a formal, slightly stiff word; in easy talk people say “you need this first” or “you have to do this before.” Though actually people stretch it.

It is a formal, slightly stiff word這是一個正式、有點生硬的字，in easy talk people say "you need this first" or "you have to do this before."口語就會說「你要先有這個」或「你要先做這件事」，Though actually people stretch it不過其實大家也會把它用得更寬鬆。

A true prerequisite is a gate: without it, the next step is not allowed or not possible. People also say it for things that merely help a lot (“a good night’s sleep is a prerequisite for a clear head”), which is looser, more like strong advice. In course catalogues it is the strict sense.

A true prerequisite is a gate真正的先決條件就像一道關卡，without it沒有它，the next step is not allowed or not possible下一步就不被允許或不可能發生。 People also say it for things that merely help a lot大家也會拿它來說那些只是很有幫助的事，("a good night's sleep is a prerequisite for a clear head")（像「睡飽是頭腦清楚的先決條件」），which is looser, more like strong advice這種用法比較鬆，比較像是強烈建議。 In course catalogues但在課程目錄裡，it is the strict sense用的就是嚴格的意思。