If I had learned it by heart ,I would have pass it !有的情況是省略了if所以句子的had提前就成了這樣：Had I learned it by heart ,I would have pass it !蓄力語氣中省略if的情況下都要倒裝,不論是與現(xiàn)在事實相...Try as she might,Sue couldn't get the door open.這是一個虛擬語氣的倒裝句，原句是As she might try,Sue couldn't get the door open。這里面好像沒有if可以省略啊。。。也要倒裝么。。。這個就不是虛擬語氣了，這個是as引導(dǎo)的讓步狀語從句，其概念為：as引導(dǎo)的讓步狀語從句必須倒裝，如果動詞貨現(xiàn)在分詞提前放在句首，謂語要補加助動詞do/does/did,will等，如： Fail as he did , he would never give up .還有as引導(dǎo)的讓步狀語從句表語是名詞的情況，這里就不多說明。我們來看這道題： 句子是as引導(dǎo)的讓步狀語從句，所以我們必須倒裝。通過上面的概念可知，我們要把動詞try提前。 于是就成了倒裝的句子。