一、虛擬語(yǔ)氣的三種最基本的用法

1.與現(xiàn)在事實(shí)相反，if引導(dǎo)的條件狀語(yǔ)從句中動(dòng)詞時(shí)態(tài)用一般過去時(shí)(be為were)，主句中的would/could/should/might+動(dòng)詞原形。

2.與過去事實(shí)相反，if從句中用動(dòng)詞的過去完成時(shí)。主句中用would/could/should/might+have+過去分詞。

3.與將來(lái)事實(shí)相反，if從句中用(1)動(dòng)詞的一般過去時(shí);(2)were to+動(dòng)詞原形;(3)should+動(dòng)詞原形。主句中用would/could/should/might+動(dòng)詞原形。如:If I had money， I would buy a car.(與現(xiàn)在事實(shí)相反。)If you had come earlier ，you could have met him，(與過去事實(shí)相反)。If it were to snow tomorrow ，the crops would be saved.( 與將來(lái)事實(shí)相反)。

二、虛擬語(yǔ)氣的特殊用法的一些總結(jié)

⒈if it be not for...如果不是……主句中用虛擬語(yǔ)氣。

If it were not for the guidance of the party committee， we should/would fail.

If it had not been for the help of our teacher， we should not have made so much progress.

If it were not for the collective strength(集體的力量)，it would not have been possible for us to live so well.

If it had not been for me，you would not be free.

2.虛擬語(yǔ)氣中條件句可以省略if，而把were，had或should移至主句之前，但如果從句中沒有were，had或should，則不能。如:

Should it happen ，what would you do?

Were I you ，I would go .

Had he recognized me， he would have come over.

3.在insist，order ，command ，suggest，advise ，propose ，recommend ， ask，demand，require ，request引導(dǎo)的賓語(yǔ)從句中，要用虛擬語(yǔ)氣。

She insisted that she(should) go alone.

The chairman proposed that we (should) put the match off.

The order came that it(should) be started at once.

It is ordered that we(should) arrive there before ten o’clock.

⒋下面兩種句型只用虛擬語(yǔ)氣

(1)It is time that clause ，主語(yǔ)從句中表示一種建議，從句的謂語(yǔ)動(dòng)詞用過去時(shí)，或should+動(dòng)詞原形，意思是“該干某事的時(shí)候了”，但“should”不可省略。

It’s time we went /should go to bed.

It’s (high) time we did/should do our homework.

(2)would rather that sb did sth

I would rather you went to that party instead of me.

I would rather he did shopping for me.

5.在帶without的介詞短語(yǔ)的句子中.

Without water ，there would be no living things.

I could nothavelivedthroughChristmaswithout giving youapresent.

6.用在so that，in order that引導(dǎo)的目的狀語(yǔ)從句中。

She spoke in a loud voice so that everyone could/might hear her clearly.

He got up early in order that he could /might catch the early bus.

7.用在as if ，as though 引導(dǎo)的非真實(shí)情況的句子中。

She felt as if she were going to die .

They were talking as if they were friends .

She speaks to me as if I were a kid .

8.在wish后的賓語(yǔ)從句中。

I wish that I had lots of money .

I wish that I would fly to the moon in a spaceship one day .

I wish that I would had passed the English exam .

9.It is important /necessary / natural ...that sb should do sth.

It is a pity / a shame /no wonder ...that sb should do sth .

It is suggested that we should finish the project by next month .

It is a great pity that he should be so careless.

10.otherwise 之后的從句中，可用虛擬語(yǔ)氣。

Give me ten million dollars ，otherwise I would burn your house down .

He isn’there ，otherwise I would give him a present.

作者單位:甘肅省蘭州市第二十三中學(xué)