Question

I didnt see your sister at home.if she ____,she would have m

Answer 1

这是条件句（CONDITIONAL SENTENCES ）的固定答配,请熟记.

英文条件句有三种基本结构：

1.现在式 ＋ 将来式

If yougo ,I'll go too.

2.过去式 ＋ 现在条件式

If you went ,I would go too.

3.过去完成式 ＋ 过去条件式

If you had gone ,I would have gone too.

你的句子属于第三种句型,所以必须用 “had come”,这是语法所规定.

如果她那天已经来了,我就一定会见到她的 .（因为她没来,所以我那天没有见到她在家）