虛擬語(yǔ)態(tài)的用法如何使用虛擬語(yǔ)態(tài)

　　虛擬語(yǔ)氣在各種結(jié)構(gòu)中的運(yùn)用是歷年三級(jí)統(tǒng)考必考的內(nèi)容，考生必須熟練掌握。以下是由學(xué)習(xí)啦小編整理關(guān)于虛擬語(yǔ)態(tài)的用法的內(nèi)容，希望大家喜歡!

　　虛擬語(yǔ)態(tài)的用法

　　一、虛擬條件句中虛擬語(yǔ)氣的運(yùn)用：

　　虛擬條件句從時(shí)間上又分為與現(xiàn)在事實(shí)相反，與過(guò)去事實(shí)相反，與將來(lái)事實(shí)可能相反三種情況。表示與現(xiàn)在事實(shí)相反的，if從句用過(guò)去式，主句用would (或could ,should ,might)加原形動(dòng)詞。與過(guò)去事實(shí)相反的，if從句用過(guò)去完成時(shí)，主句用would(或could ,should ,might)+have done結(jié)構(gòu)。與將來(lái)事實(shí)可能相反的，if 從句用should (或were to )加動(dòng)詞原形，主句用would加動(dòng)詞原形。

　　1、If a better material _____, the strength of the part would have been increased.

　　A. had been used

　　B. had been using

　　C. being used

　　D. using

　　(根據(jù)前面的講解，正確答案為A。)

　　2、Had the weather been good, the children _____ out for a walk.

　　A. had gone

　　B. could have gone

　　C. would go

　　D. went

　　(答案：B。與過(guò)去的事實(shí)相反。當(dāng)if從句中含有were, had, should這三個(gè)詞時(shí)，if可以省略，主謂倒裝。)

　　二、某些動(dòng)詞后的賓語(yǔ)從句以及某些名詞后的表語(yǔ)或同位語(yǔ)從句中虛擬語(yǔ)氣的運(yùn)用，這些動(dòng)詞或名詞包括：

　　suggest (suggestion),propose(proposal),advise (advice)demand, insist, order, request, require, recommend, desire, ask, decide等。在這些從句中，謂語(yǔ)形式為should加動(dòng)詞原形，should可以省略。

　　例：The general’s command was that the soldiers _____ their fort and carry out more important task.

　　A. would leave

　　B. leave

　　C. left

　　D. have left

　　(答案：B)

　　三、在It is desired (或desirable), It is important等結(jié)構(gòu)后面的主語(yǔ)從句中，動(dòng)詞用原形或should+原形動(dòng)詞。這些結(jié)構(gòu)有：

　　“It is suggested”, “It is requested”,“It was ordered”, “It is necessary”, “It is essential”, “It is vital”, “It is urgent”,“ It is impossible”, “It is preferable”, “It is advisable”, “It was proposed”等。

　　例：It’s desired that she _____ to teach us at least twice a week.

　　A. comes

　　B. will com

　　C. come

　　D. may come

　　(答案：C)