文/普通的馬兒
在《星火英語語法全解》中，虛擬語氣的定義是：在表示虛假的、與事實(shí)相反的或難以實(shí)現(xiàn)的情況時(shí)；表示主觀愿望或表示某種強(qiáng)烈情感時(shí)，用虛擬語氣。
一、真實(shí)條件句中的虛擬語氣（說話者不確定是否與事實(shí)相符）
If I have enough money,I will go to the zoo with you.
如果我有足夠的錢，我會(huì)和你一起去動(dòng)物園的。（說話者不確定錢夠不夠，“我得數(shù)一數(shù)錢是否足夠，如果夠我就去?！保?/p>
If we get caught,we will be expelled.
如果我們被抓到，我們會(huì)被開除。（會(huì)不會(huì)被抓到并不知道）
二、非真實(shí)條件句中的虛擬語氣
1.與現(xiàn)在事實(shí)相反的虛擬語氣
If I were a bird, I would fly.
如果我是只鳥，我一定能飛。
If I had enough money,I would first of all buy myself a computer.
如果我有足夠的錢，我首先為自己買一臺(tái)電腦。
If there were no clouds,we should not enjoy the sun.
如果沒有陰云密布，我們就不會(huì)享受陽光。
與現(xiàn)在事實(shí)相反的虛擬語氣常用結(jié)構(gòu)為：If引導(dǎo)的條件從句中的動(dòng)詞用過去式（be的過去式用were），主句動(dòng)詞為“would/should/could/might+動(dòng)詞原形”。
2.與過去事實(shí)相反的虛擬語氣
I would have told you yesterday if you had been here.
如果你當(dāng)時(shí)在這兒的話，我昨天就告訴你了。
If ?you had worked hard, you would have easily passed the final examination.
如果你當(dāng)時(shí)努力學(xué)習(xí)的話，就會(huì)輕松通過期末考試的。
If we had had enough rain last year,we could have gained a good harvest.
如果去年雨水充足的話，我們可能會(huì)有一個(gè)好收成。
與過去事實(shí)相反的虛擬語氣常用結(jié)構(gòu)為:If引導(dǎo)的條件從句中的動(dòng)詞用“had+過去分詞”，主句動(dòng)詞用“would/should/could/might+have+過去分詞”。
3.與將來事實(shí)相反的虛擬語氣
If I should see/were to see/saw him tomorrow,I would invite him home.
如果明天見到他，我會(huì)邀請(qǐng)他到我家。（事實(shí)是明天我見不到他）
If it should be/were fine tomorrow,I would go on a trip.
如果明天天氣好的話，我要去旅游。（事實(shí)是明天天氣無法好起來）
This printer is of good quality.If it should break down within the first year,we would repair it at our expense.
這臺(tái)打印機(jī)質(zhì)量很好。如果一年內(nèi)出現(xiàn)問題，我們將免費(fèi)維修。
與將來事實(shí)相反的虛擬語氣常用結(jié)構(gòu)為：If引導(dǎo)的從句中的謂語可用“動(dòng)詞過去式、should+動(dòng)詞原形、were to+動(dòng)詞原形”，主句用“would/should/could/might+動(dòng)詞原形”。
從句中的should表示的可能性最大，動(dòng)詞過去式的可能性次之，were to do的可能性最小。
主句中的would表示必然的結(jié)果，could表示能夠，might表示可能的結(jié)果。
三、非真實(shí)條件句省略If的情況
If I had worked hard,I would have surely successed.=
Had I worked hard,I would have surely succeed.
如果我當(dāng)時(shí)努力學(xué)習(xí)的話，我肯定會(huì)成功的。
If time were to go back,I would study double hard.=
were time to go back,I would study double hard.
如果時(shí)光能倒流，我會(huì)加倍努力。
If she should be my daughter,I wouldn't allow her to study abroad.=
Should she be my daughter,I wouldn't allow her to study abroad.
如果她是我的女兒，我就不讓她出國學(xué)習(xí)了。
當(dāng)非真實(shí)條件句中有should,had,were時(shí)，可以省if,而把should,had,were提至主語前，形成部分倒裝。
四、虛擬語氣常用句式
Were it not for you help,I would never be a good manager.
要不是你的幫助，我永遠(yuǎn)也成不了好經(jīng)理。
Had it not been for you,I would have lost my way.
當(dāng)時(shí)要不是你，我就迷路了。
Were it not for...“如果要不是……”，Had it not been for...“當(dāng)時(shí)要不是……”兩者均是虛擬語氣的常用句式。
更多虛擬語氣知識(shí)，請(qǐng)參考原著。
作者：普通的馬兒 小學(xué)英語教師，喜歡研究各種學(xué)習(xí)方法，喜歡閱讀小說，總想寫點(diǎn)什么的待產(chǎn)孕媽。
計(jì)劃每日寫一篇文章，每日復(fù)習(xí)新學(xué)英語單詞200個(gè)，每周學(xué)一首英文歌。
