1. at night 用于表示惯常在夜间发生的事,例如:
Nocturnal animals such as bats and owls only come out at night. 夜行动物如蝙蝠和猫头鹰只在夜间才出来。
I don’t like driving at night. 我不喜欢夜晚开车。
2. by night 用于强调某活动的条件或环境,意思是“趁夜间/夜里(做某事)”,例如:
The enemy attacked by night. 敌人趁夜袭击。
3. in the night 通常指刚刚过去的那个夜晚,例如:
I’m exhausted, the baby woke up three times in the night. 我累坏了,孩子夜里醒了三次。
也可以用 during the night 来替换,例如:
Everything was quiet during the night/in the night. 昨夜万籁寂静。
参考《牛津高阶英汉双解词典》。
1. at night 意思是“在夜里”、“上半夜”。例如:
We sleep at night. 我们夜里睡觉。
2. by night 意思是“夜里”,往往指“利用黑夜”,与 by day (白天)相对。例如:
These small animals sleep by day and hunt by night. 这些小动物昼伏夜出猎食。
3. in the night意思是“这天夜里”,与in the day time (白天)相对。例如:
I woke up twice in the night. 我夜里醒过两次。
(《薄冰英语惯用法词典》)