“如果以前做了某事” 虚拟语态

Question

是If I would have done... 吗？

Answer 1

If I had done sth,I would have ....你说的那个从句只是主句,而不是从句.
还有别的表示虚拟语气的方法，如关键词：but for.../had I done sth ,I'd have+过去分词．

Answer 2

表示于过去事实相反的假设。
句型： 条件从句(if had+done) ,主句(would have done)
过去完成时 should(would) have+ 过去分词

例子:
If she had worked harder, she would have succeeded.

hope this can help!本回答被提问者采纳

Answer 3

If I had done sth before, I would have ....应该是这个句型吧

Answer 4

if i had done sth.earlier