■at night 的意思是 during any night，通常表泛指。如：
I often work at night. 我经常在夜间工作。
He’s afraid to go out alone at night. 他害怕夜晚独自出去。
It’s becoming dangerous to go out alone at night. 夜间独自外出已经越来越危险了。
Please ensure that all the lights are switched off at night. 夜间请务必将所有的灯关掉。
在非正式文体中，有还可用复数名词不加介词来指反复进行的活动。
Would you rather work nights or days? 你愿意上夜班还是上白班?
■in the night的意思是 during one particular night，通常表特指。如：
单词：at night的近义词、反义词、形近词辨析
at night/in the night/on the night
Ever since then,the bat comes out only at night.从那时起，蝙蝠只在夜里出来。
She came back at eleven in the night.他在夜里十一点钟回来。
The story happened on the night of October 25,198故事发生在1980年10月25日深夜色。
<辨析>at night 泛指在夜晚，是 in the day （白天）的反义词，night 前不用冠词。in the night 指某个夜晚，但不具体，night 前有冠词 the。one the night 指一个特定的夜晚。表示特定的方法有两种：1)在 night 后面有 of 短语加以限制，如 on the night of that terrible storm,在那个暴风雨的夜晚；2)在 night 前有修饰语，如：on a cold night，一个寒冷的夜晚。
与单词：at night 相关的例句或者名人名言
He stayed up late at night with his book, just so he could finish reading the tale.
他晚上熬夜，就是为了能看完书上的这个故事。
However, at night it is easy to be carried away.
可是当黑夜来临时，还是很容易被有心人背着拿走。
They usually keep a light on at night.
他们通常夜里开着灯。
※At night, all cats are grey. 猫在夜晚皆灰色(丑妍暗中难分辨)。
※Misfortunes come at night. 灾祸常生于不测。
