Vigilant describes a person (or a group, or a country) who is watching carefully all the time, so that if something dangerous or wrong starts to happen, they will notice it. It is the adjective that goes with vigilance.

Vigilant用來形容 a person (or a group, or a country)一個人（或是一個團體、一個國家） who is watching carefully all the time都一直很仔細地在注意著， so that這樣一來 if something dangerous or wrong starts to happen萬一有危險或不對的事情開始發生， they will notice it他們就會發現。It is它是 the adjective that goes with vigilance搭配名詞vigilance（警覺性）的形容詞。

It carries the idea of alertness held over time, not just a single moment of noticing, and it almost always looks toward trouble — you are vigilant against danger, crime, cheating, illness, mistakes. You would not say someone is vigilant about the beautiful view.

It carries the idea of它帶著這樣的概念： alertness held over time長時間保持著警覺， not just a single moment of noticing不只是一時注意到而已， and it almost always looks toward trouble而且幾乎都是針對麻煩事在說的—— you are vigilant against danger, crime, cheating, illness, mistakes對危險、犯罪、作弊、疾病、失誤保持警覺。 You would not say你不會說 someone is vigilant about the beautiful view有人對美麗的風景「vigilant」（保持警覺）這種話。

The word is formal-ish; in ordinary conversation people say 'keep an eye on', 'watch out', 'stay alert'. But 'stay vigilant' and 'remain vigilant' turn up constantly in official warnings, so most learners meet it there first.

The word is formal-ish這個字有點正式， in ordinary conversation平常講話時 people say大家會說 'keep an eye on', 'watch out', 'stay alert''keep an eye on'（盯著點）、'watch out'（小心）、'stay alert'（保持警覺）。 But不過 'stay vigilant' and 'remain vigilant''stay vigilant'、'remain vigilant' turn up constantly in official warnings常常出現在官方的警告裡， so most learners meet it there first所以大多數學習者都是先在那裡遇到這個字的。

Grammar: it is used before a noun ('a vigilant guard') or after be/stay/remain ('we must remain vigilant'). What you are watching for takes 'against' or 'for': 'vigilant against fraud', 'vigilant for signs of infection'. The adverb is vigilantly, the noun vigilance.

Grammar文法上： it is used before a noun它可以放在名詞前面（'a vigilant guard''a vigilant guard'，警覺的守衛） or after be/stay/remain也可以放在be/stay/remain後面（'we must remain vigilant''we must remain vigilant'，我們必須保持警覺）。 What you are watching for你在防範什麼 takes 'against' or 'for'要用'against'或'for'來接： 'vigilant against fraud''vigilant against fraud'（提防詐騙）、 'vigilant for signs of infection''vigilant for signs of infection'（留意感染的跡象）。 The adverb is vigilantly副詞是vigilantly， the noun vigilance名詞是vigilance。