on night 不能单独使用, 必须有具体的东西修饰night 才能用on,
即具体到哪一天的夜晚
at night 就泛指夜晚....没有特定...可以单独使用。at night 单独使用,
如在某个具体的晚上则用介词on 如:
on Sunday night 在星期日晚上,
on night 这个词组是没有的。on 只有当night 前有词修饰它时才可以用，例如：On Friday night.（指具体的某一晚）
“At night”和“in the night”都是副词性的介词短语，意思没有什么差别。例如：
(1) at night : when night comes(晚上；夜间) “Some animals in the zoo can only be seen at night.
(2) in the night : during the night (在夜间)
(a) 'Why are the roads so wet this morning? It must have rained in the night.”
(b) 'We sleep during the night; we work during the day.”
at night 就泛指夜晚....没有特定...可以单独使用。at night 单独使用,
如在某个具体的晚上则用介词on 如:
on Sunday night 在星期日晚上,
on night 这个词组是没有的。on 只有当night 前有词修饰它时才可以用，例如：On Friday night.（指具体的某一晚）
“At night”和“in the night”都是副词性的介词短语，意思没有什么差别。例如：
(1) at night : when night comes(晚上；夜间) “Some animals in the zoo can only be seen at night.
(2) in the night : during the night (在夜间)
(a) 'Why are the roads so wet this morning? It must have rained in the night.”
(b) 'We sleep during the night; we work during the day.”