哈利波特里有一句话fine thing it would be if, on the very day you-know-who seems to have gone, the muggles found about us. 这句话假如不需要seems，是该说on the very day you know who has gone,还是该说left.该用完成时还是过去时？the very day指的是今天。
你的句子是否漏掉了一些词汇。这句话的正常语序是：
It would be a fine thing if, on the very day you-know-who seems to have gone, the muggles found out about us all.
【翻译】就在“你认识的那个人”仿佛已经离去的那一天，麻瓜已经查明了大家所有人的底细，果真这样的话，那将是好事。
【剖析】
1. 主句：It would be a fine thing
2. 条件从句：if, on the very day you-know-who seems to have gone, the muggles found out about us all.
3. 在条件从句中，又包括一个“时间从句 + 主句”。
时间从句：on the very day you-know-who seems to have gone（就在......那一天。严格的说，you-know-who seems to have gone 是day 的定语从句。）
主句：the muggles found out about us all
you-know-who：是一个单词，意思是“你认识的那个人”，不可分开理解。
4. 假如不说seems，那样句子就是一般过去时：on the very day you-know-who went，
