at night, by night, in the night, on the night
这四个短语共同的意思是“在夜里”。它们的区别是：
at night泛指夜晚; in the night表示“当天夜里”,与in the day time相对; on the night特指某天夜里,尤指上半夜,与in the morning相对; by night常含“利用夜晚”的意思,与by day相对。例如:
The baby woke up twice in the night.这婴儿在夜里醒了两次。
I went to see a film on the night of March 5.3月5日夜里我去看电影了。
The army attacked at night when the enemy was asleep.在夜间敌人熟睡时军队发起了攻击。
The thief stole money by night.小偷利用夜晚作案。
night, evening
这两个词共同的意思是“晚上”。它们的区别是：
night指从睡觉起到第二天一早这段时间; evening指从黄昏到睡觉前这段时间。
Good night,Good evening
这两个短语的区别是：
1.Good night是晚上分别时的用语(无论时间有多早),意思是“晚安”; Good evening是晚上见面时的用语(无论时间有多晚),意思是“晚上好”。
2.Good night有时用作感叹语,表示惊讶。例如:
The man's eyes opened wide when he saw the big fish his little boy had caught, and said,“Good night!”这个人看到他的小儿子捉到一条大鱼时,眼睛睁得老大地说：“好家伙!”
下面两句话的意思相同：
I work nights and I am free in the after- noon.
I work at night and I am free in the after- noon.
我晚上干活,下午没事。
在美式英语中, nights与at night同义,且有强调意味。
