5. 以上句型可以轉換成以下形式：

　　1)條件狀語從句省略if：在書面語中，如果條件狀語從句的謂語中有were, had 或should, 就可以省略if, 并將were, had 或should 放到句首，謂語主語之前，用 “Were/Had/Should + 主語”的形式。這種虛擬語氣在意義上與帶if 的條件狀語從句相同。當然，如果從句沒有were, had, 或should,就不能省略if.

　　Now let’s look at some examples:

　　If I were to do it, I’d do it some other way. →Were I to do it, I’d do it some other way.

　　If you should fail, try again. →Should you fail, try again.

　　If you had been here earlier, you would have seen him. →Had you been here earlier, you would have seen him.

　　但是，If you came tomorrow, we would have the meeting.這句話if 就不能省略。

　　而且，在虛擬條件狀語從句中，省略了if的倒裝形式的句首不能用動詞的縮略形式。如我們可以說：

　　Were it not for the expense, I would go to Italy.

　　但不能說：Weren’t it for the expense, I would go to Italy.

　　Please do not use “if”：

　　如果我是你，我每天早上就早起床。

　　Were I you, I would get up early every morning.

　　假如你昨天早十分鐘到達火車站，你就趕上火車了。

　　Had you arrived at the station ten minutes earlier yesterday, you could have caught the train.

　　要是明天有會議，我就會來。

　　Should there be a meeting, I would come.

　　2)用介詞短語代替條件狀語從句。(可以改為條件狀語從句)。例如：

　　Without air, there would be no living things.

　　But for your help, I couldn’t have done it.

　　Without electricity human life would be quite different today.

　　Now let’s do some translation. 請用介詞短語代替條件狀語從句。

　　要不是你的幫助，我就失敗了。

　　But for (except, without) your help, I would have failed.

　　如果沒有恰當的控制手段，核反應堆就會爆炸。

　　Without proper means of control, a nuclear reactor would explode.

　　3)用其他方式代替條件狀語從句(可以改寫為條件狀語從句。)例如：

　　It would produce bad results to do that. 用動詞不定式 =If you did that/should do that, it would produce bad results.

　　She would have come, but she wasn’t informed, nor invited. (用but.)=She would have come, if she had been informed or invited.

　　A more responsible person would not have left the work half done. 一個更負責的人是不會把工作做到一半就不管的。(用比較級) =If you (he, she) were more responsible, you (he, she) would not have left the work half done.

　　Now let’s do some translation:

　　聰明一點的人是不會干出這等蠢事的。

　　A wiser man would not have done such a foolish thing.

　　我應該早點寫完這封信，但我一直很忙。