由下列名詞或短語(yǔ)引導(dǎo)，或含有某些詞的從句中應(yīng)用的虛擬語(yǔ)氣

1.“Iest 以免、惟恐”引導(dǎo)的從句用“should+動(dòng)詞原形”。

He took a map with him lest he (should ) lose his wag there.

2.“whether不管、無(wú)論”引導(dǎo)的讓步狀語(yǔ)從句，有時(shí)用動(dòng)詞原形。

All things, whether you know or don’ t know, exist in the world.

3.用“would rather/had rather’ would just as soon"表示“寧愿、但愿”，后面的賓語(yǔ)從句謂語(yǔ)用過(guò)去式或動(dòng)詞原形表示對(duì)將來(lái)的要求，用過(guò)去時(shí)表示對(duì)現(xiàn)在的愿望，用過(guò)去完成時(shí)表示對(duì)過(guò)去做的事的懊悔。

Don’ t live in the world, I would rather( I would just as soon) you die.

I would rather you go tomorrow.

I would rather everything hadn’ t happened in the past.

4.用“had hoped”表示原來(lái)希望做到而實(shí)際上未能實(shí)現(xiàn)的事情，其賓語(yǔ)從句的謂語(yǔ)用“would+動(dòng)詞原形”。

I had hoped that she would go to the U.S. and study there, but she said she liked to stay in China.

5.在“It is(high/about)time+that”引導(dǎo)的定語(yǔ)從句中，定語(yǔ)從句的主謂語(yǔ)用一般過(guò)去時(shí)，偶爾也可以用would(或should)+動(dòng)詞原形，或had rather (would rather)+動(dòng)詞原形。

It is hihg (about)time that we left/should leave/ had better leave/had rather leave/ were leaving.(注意與“This is the first/second…time”后從句中用現(xiàn)在完成時(shí)的區(qū)別。

6.用“without/but for/in the absence of ”表示“要不是”，“如果沒(méi)有”(相當(dāng)于if it were not for…)表示條件時(shí)，句中一般用虛擬語(yǔ)氣。(也可用陳述語(yǔ)氣)

Without your help, I couldn’ t finish my work on time.

In the absence of water and air, nothing could live.

7.由“providing (that)/ provided (that)/on condition that/ in order that”引導(dǎo)的條件從句或目的從句，根據(jù)情況，可用虛擬語(yǔ)氣。(有時(shí)也可用陳述語(yǔ)氣)

They are willing surrender provided they are given free passage. if ,將were等提到主語(yǔ)前，形成倒裝。

Should there be a good film tomorrow. I would go to the theatre with you.

Were it not for your help. I wouldn’ t be succeed.