虛擬語（yǔ）氣

一．虛擬語氣在條件句中的用法:

    條件句有真實（shí）條（tiáo）件句和非真實條件句兩種。

1. 在條件句中的應用

條件句可（kě）分為兩類，一類為真實條件（jiàn）句，一類為非真實條件句。

A 真實（shí）條件句

真實條件句用於陳述（shù）語（yǔ）氣，假設的情況可（kě）能發（fā）生。

時態關係

句型：條件從句       主句

      一般現在（zài）時     shall/will+動詞原形（xíng）

If he comes, he will bring his violin.

典型例題

The volleyball match will be put off if it_______.

A. will rain    B. rains    C. rained    D. is rained

答案（àn）B。真實條件句主句為將來時，從句用一（yī）般現在時。

注意：

（1）       在真實條件句中，主句不能用be going to表示將來，該用shall, will.

（2）       表示真理時，主句謂語動詞不用shall(will)+動詞原形，而直接用（yòng）一（yī）般現在時的動詞（cí）形式。

B 非真實條件句

 非真實條件句（jù）所表的假設則是不可能或不大可能發生或實現的，句中的條件從句與結果主句皆用虛擬語氣。

1. 表示跟現在事實相反

  從句的謂語用（yòng）動詞的過去式（be的過去式用were），構成If I （we, you, he, they）＋動詞過去（qù）式的形式；

If I were you, I should (would, could, might)tell him the truth.

 If he had time, he would (could, might) go with you.

2. 與過去的（de）事實（shí）相反

   從句的謂語用had＋過（guò）去分詞，構成If I (we, you, he, they)＋had＋過去分詞的形式；主句的謂語用should（第（dì）一人稱（chēng））/would（第二、三人稱）/could/might have ＋動詞過去分詞。

如果你仔細一點， 這個錯誤是可以避免的. 例如：

If I had time last night, I should have come to see you.

He would never have behaved like that if he had had a good education.

3. 與將來事實相反

    從句（jù）的謂（wèi）語用（yòng）If I (we, you, he, they) ＋動詞過去式（shì）或were to do 或should do 形式，主句（jù）謂語用should（第一人稱）/would（第二、三人稱）/could/ might ＋動詞原形。例如：

If he were to come, what should we say to him.

If we climbed to the top of the mountain, should we get a good view?

4. If從句中若含有should, had 或（huò）者were，那麽就可以把它們放在（zài）句首，與主（zhǔ）語顛倒形（xíng）成倒裝，但動詞過去式不可以與主語倒裝。例如：

Were he here, he would come to help us.

Had you been here just now, you would have met her.

5. 當條（tiáo）件狀語（yǔ）從句（jù）表示的行為和主句表示的（de）行（háng）為所發（fā）生的時間不（bú）一致時，被稱為“錯綜時間條件（jiàn）句（jù）”，動詞的形式（shì）要根據它所表示的時間作出相應的調整。例如：

If he had set out earlier, he would be home now.

If I were not busy, I would have come.

6. 用介詞短語代替條件狀語從（cóng）句。常用的介詞由with, without, but for等。例（lì）如：

We couldn’t have finished the work ahead of time without your help. (＝if we hadn’t got your help)

7. 含蓄條件句

有（yǒu）時為了表達（dá）的需要，在虛擬語（yǔ）氣中並不總是（shì）出現if引導的條件句，而通（tōng）過其他手（shǒu）段代替條件句。例如：

I was ill that day. Otherwise, I would have taken part in the sports meet.（副詞）

He telephonesd to inform me of your birthday, or I would have known nothing about it .（連詞）