你说的是含有虚拟语气的倒装句吗?如果是,请看下面的句子：
1) Had I known his phone number,I would have called him yesterday.
如果我当时要是知道他的电话号码,我昨天就打电话了.
=If I had known his phone number,I would have called him yesterday.
2) Were I you,I would do it in a different way.
如果我是你,我就用不同的方法去做.
=If I were you,I would do it in a different way.
3) Should you meet her this afternoon,do tell her about it.
如果你今天下午玩一见到她,一定要把这件事告诉她.
=If you should meet her this afternoon,do tell her about it.