虛擬語(yǔ)氣在非真實(shí)條件狀語(yǔ)從句中的用法及動(dòng)詞形式
① 表示與現(xiàn)在事實(shí)相反的情況
（條件）從句謂語(yǔ)動(dòng)詞形式 主句謂語(yǔ)動(dòng)詞形式
謂語(yǔ)動(dòng)詞用一般過(guò)去式
（be用were） should/would/could/might+動(dòng)詞原形（過(guò)去將來(lái)時(shí)）
eg.
If I were you,I would take an umbrella.如果我是你,我會(huì)帶把傘.（事實(shí)：我不可能是你）
If I knew his telephone number,I would tell you.如果我知道他的電話號(hào)碼,我就會(huì)告訴你.（事實(shí)：不知道）
If there were no air or water,there would be no living things on the earth.如果沒(méi)有水和空氣,地球上就不會(huì)有生物.(事實(shí)：地球上既有空氣也有水)
If I had any money with me,I could lend you some.如果我?guī)уX了,我就會(huì)借給你些.（事實(shí)：沒(méi)帶錢）
If he studied harder,he might pass the exam.如果他再努力些,就能通過(guò)考試了.（事實(shí)：學(xué)習(xí)不用功）
②表示與過(guò)去事實(shí)相反的情況
從句謂語(yǔ)動(dòng)詞形式 主句謂語(yǔ)動(dòng)詞形式
had+過(guò)去分詞（過(guò)去完成時(shí)） should/would/could/might+
have+過(guò)去分詞（現(xiàn)在完成將來(lái)時(shí)）（過(guò)去將來(lái)完成時(shí)）
eg.If I had got there earlier,I should/could have met her.如果我早到那兒,我就會(huì)見(jiàn)到她.（事實(shí)：去晚了）
If he had taken my advice,he would not have made such a mistake.如果他聽(tīng)我的勸告的話,就不會(huì)犯這樣的錯(cuò)誤了.（事實(shí)：沒(méi)有聽(tīng)我的話）
③表示對(duì)將來(lái)情況的主觀推測(cè)（可能相反或可能性很?。?br/>從句謂語(yǔ)動(dòng)詞形式 主句謂語(yǔ)動(dòng)詞形式
If+主語(yǔ)+ ① should+動(dòng)詞
② did
③were to do
(①通常與一個(gè)表示時(shí)間狀語(yǔ)連用)其 中were to do可能性最小,
should/would/could/might+動(dòng)詞原形
eg.If he would come here tomorrow,I should/would talk to him.如果他哪天來(lái)這兒的話,我就跟他談?wù)?（事實(shí)：來(lái)的可能性很小）
If there were a heavy snow next Sunday,we would not go skating.如果下周日下大雪,我們就不能去滑冰了.（事實(shí)：不知能否下雪）
If she were to be there next Monday,I would tell her about the matter.如果她下周一來(lái)這兒的話,我就會(huì)告訴她這件事得始末.
在表示建議、命令、要求等含義的賓語(yǔ)從句,謂語(yǔ)動(dòng)詞常用虛擬語(yǔ)氣,"should＋動(dòng)詞原形"構(gòu)成,should 可省略.