两者的意思都是“在上学的晚上”，on school nights 是on school night 的复数形式。 1.on school nights 例：On school nights, my mom makes me go to bed at 9: 00. 在上学的夜晚，我的妈妈让我9点睡觉。 I'm not to go out on school nights, . 上学时的晚上也不让我外出。
2.on school night 例：Why? Were you out at a party on a school night? 为什么？你昨晚出去参加晚会了吗？ We can't be staying out this late on a school night. 在学校，我们不准这么晚才回来。