1.caution的基本意思是告诉人们即将来临或可能出现的危险与风险,强调建议别人提高警惕预防不测。依据对象和语气的不同,可分别译为“提醒”“劝…小心”。
2.caution是及物动词,可接名词、代词或从句作宾语,也可接双宾语。还可接以动词不定式(含to be)充当补足语的复合宾语。
3.caution的宾语后常接介词about或against,表示“就…警告某人”“警告某人不要做…”。

caution about(v.+prep.)
就(某事)警告(某人) warn (sb) officially about (sth)
▲caution sb about sth
The weather-forecaster cautioned us about the icy roads.气象预报员提醒我们注意结冰后的道路。

caution against(v.+prep.)
警告(某人)不要做(某事) warn (sb) officially against (doing sth)
▲caution sb against sth/v-ing
I cautioned him against the danger.我警告他当心危险。
They cautioned him against the danger of going home so late.他们提醒他这么晚回家是危险的。
He cautioned us against playing in that busy street.他告诫我们不要在那条交通繁忙的街道上玩耍。
◇ 用于be ～ed结构
We were cautioned against using that bridge.有人警告我们不要从那座桥上过去。

caution for(v.+prep.)
警告(某人)不要做(某事) warn (sb) officially against (doing sth)
▲caution sb for sth/v-ing
The policeman cautioned me for speeding.警察警告我今后不要再开快车。
◇ 用于be ～ed结构
He was cautioned for drunken driving.他因酒后开车受到警告。

用作及物动词
▲S+～+n./pron.
The judge cautioned the prisoner.法官警告了那个囚犯。
The policeman cautioned that angry driver.警察对那个怒气冲冲的司机给予警告。
▲S+～+that-clause
He cautioned that the Russia-American discussions were still in an exploratory stage.他警告说俄美商谈尚处于探索阶段。
用作双宾动词
▲S+～+n./pron.+that-clause
I caution you that you are trespassing.我提醒你,你已非法闯入私人的领地。
The policeman said,“I must caution you that anything you say may be used against you at your trial.”警察说:“我要提醒你,你说的任何一句话都可能在审判时对你不利。”
用作宾补动词
▲S+～+n./pron.+to-v
She cautioned the driver to take note of speed.她告诫司机注意车速。
The veteran worker cautioned me not to inspect the machine without turning off power.老工人告诫我要关掉电源后才能检查机器。
He cautioned me not to drink.他告诫我不要喝酒。
I cautioned him not to be late.我警告他不要迟到。
◇ 用于be ～ed结构
We were cautioned not to drive fast.我们得到告诫不要快速行车。
He was cautioned to speak as little as possible.有人警告他尽量少讲话。
The customers were cautioned to take precautions against pickpockets.顾客们被警告提防扒手。
Hait was cautioned not to be lazy.海特被警告别懒惰。

caution, advise
这组词都有“劝告”的意思。其区别在于:
1.advise的意思是“建议”“劝告”“忠告”; caution的意思是“警告”“告诫”。
2.advise指依据个人的经验、学识或正确判断而提出的供人参考的肺腑之言,希望被人接受；caution则强调给人以警告,使其防范某人或某物,或采取某行动。
caution, forewarn, warn
参见warn条。

注意下列两句意思相同:
He cautioned us against drinking the water.
He cautioned us not to drink the water.
他警告我们不要喝那水。

［同义词］ n. advice, warning
［反义词］ n. carelessness
［词源］＜古法语和拉丁语cautio(意识到)

You should exercise extreme caution when driving in rain.在雨中开车要极为小心。
His gesture indicated a caution.他的手势表示警告。