虛擬語氣--教案.doc

虛擬語氣適用學(xué)科英語適用年級(jí)初三適用區(qū)域通用課時(shí)時(shí)長（分鐘）1課時(shí)/60分鐘知識(shí)點(diǎn)1、與現(xiàn)在事實(shí)相反的虛擬條件句； 2、與過去事實(shí)相反的虛擬條件句； 3、與將來事實(shí)相反的虛擬條件句； 4. if引導(dǎo)的虛擬條件句。教學(xué)目標(biāo)知識(shí)：掌握虛擬語氣的基本用法和if引導(dǎo)的虛擬條件句.方法：要牢記虛擬語氣的基本用法和if引導(dǎo)的虛擬條件句的規(guī)則.能力：1、分清三種（與現(xiàn)在，過去，將來事實(shí)相反）情況下的虛擬語氣；2、掌握if引導(dǎo)的虛擬條件句。教學(xué)重點(diǎn)1.與現(xiàn)在事實(shí)相反的虛擬條件句； 2、與將來事實(shí)相反的虛擬條件句。教學(xué)難點(diǎn)1.與過去事實(shí)相反的虛擬條件句； 2. if引導(dǎo)的虛擬條件句。教學(xué)過程一、課堂導(dǎo)入老師將下列句子呈現(xiàn)給學(xué)生，學(xué)生跟著老師讀下列句子。1. If it should fail, I would try again.2. If it were not raining, we should go for a picnic.3. She would have gone to the party if she had been invited.二、復(fù)習(xí)預(yù)習(xí)教師引導(dǎo)學(xué)生復(fù)習(xí)上節(jié)課所學(xué)的賓語從句的概念，賓語從句的語序，賓語從句的時(shí)態(tài)和連接詞。（以提問、回顧的形式進(jìn)行），針對上節(jié)課的作業(yè)進(jìn)行講評(píng)、訂正、答疑，并通過賓語從句的具體用法的分析和擴(kuò)展導(dǎo)入本節(jié)課所要學(xué)習(xí)的虛擬語氣。三、知識(shí)講解知識(shí)點(diǎn)1：由if引導(dǎo)的虛擬語氣在條件句中的應(yīng)用1.【考查點(diǎn)】與現(xiàn)在事實(shí)相反的虛擬條件句，條件從句的謂語用動(dòng)詞的過去式 (be的過去式用were), 主句的謂語用should （would, might， could）+動(dòng)詞原形。如：If it were not raining, we should go for a picnic.如果現(xiàn)在不下雨的話，我們就出去野餐了。（事實(shí)是：天在下雨，我們不能出去野餐。表示愿望。）If he came here, he might be able to help you. 如果他來這，他就能夠幫助你了。（事實(shí)是：他沒來這，他不可能幫助你。表示對他的良好印象。）2. 【考查點(diǎn)】與過去事實(shí)相反的虛擬條件句，條件從句的謂語用had+過去分詞，主句的謂語用should （ would, might， could）+ have 過去分詞。如：She would have gone to the party if she had been invited. 要是當(dāng)初她被邀請的話，她就會(huì)去參加這次聚會(huì)了。（事實(shí)是：當(dāng)時(shí)沒有人邀請她，因此，她沒有來參加聚會(huì)。表示后悔。）3.【考查點(diǎn)】與將來事實(shí)可能相反的虛擬條件句，條件從句的謂語用動(dòng)詞的過去式 (be的過去式用were)； should動(dòng)詞原形；were to動(dòng)詞原形，主句用should （would, might， could）+動(dòng)詞原形。如：If it should fail, I would try again. 要是失敗了，我會(huì)再試一次。（事實(shí)是：有可能失敗，可我會(huì)再試。表示未知。）4. 【考查點(diǎn)】混合型的條件句當(dāng)條件從句與主句所表的時(shí)間不一致時(shí)，虛擬語氣的形式應(yīng)作相應(yīng)的調(diào)整。主句和從句的謂語動(dòng)詞并不相互呼應(yīng)，這種條件句叫混合條件句。較多見的混合型條件句是從句用過去完成時(shí)（指過去行為），而主句用一般時(shí)（指目前狀態(tài)）。如：He would pass the test if he had taken my advice如果他聽了我的勸告，他現(xiàn)在會(huì)通過考試。You would be much better now if you had taken my advice. 假如你接受了我的意見，你現(xiàn)在就會(huì)好得多。注：如條件從句用if I were.，主句則可用表任何時(shí)間的虛擬形式。如：If I were not busy, I would have come.假如我不忙，我就會(huì)去了。(were表過去)If I were you, I would go.假如我是你，我會(huì)去的。(were表現(xiàn)在)知識(shí)點(diǎn)2：連詞if的省略【考查點(diǎn)】如果虛擬條件句的謂語部分有were，had和should時(shí)，可省略if，把were，had和should放到從句主語前面去，多見于書面語。如：Had you not helped me， I should have failed.要是沒有你的幫助，我就失敗了。Were you in my position, you would do the same. 假如你處在我的地位，你也會(huì)這樣干的。Should they attack us, well wipe them out completely. 假如他們進(jìn)攻我們，我們就把他們徹底消滅干凈。知識(shí)點(diǎn)3：含蓄條件句虛擬條件句中的條件從句有時(shí)不表出來，只暗含在上下文中，這種句子叫做含蓄條件句。含蓄條件句大體有三種情況。1. 【考查點(diǎn)】條件暗含在短語中。如：But for your help we couldnt have succeeded in the experiment. 如果沒有你的幫助，我們的實(shí)驗(yàn)是不會(huì)成功的。(暗含在分詞短詞but for your help)What would I have done without you? 如沒有你，我會(huì)怎么辦呢？(條件暗含在介詞短語without you 中)It would be easier to do it this way. 這樣做會(huì)比較容易。(條件暗含在不定式短語 to do it this way中)Alone, he would have been terrified. 如是單獨(dú)一人，他是會(huì)感到害怕的。(暗含條件是alone)2.【考查點(diǎn)】 條件暗含在上下文中。如：You might stay here forever. 你可以永遠(yuǎn)待在這兒。(可能暗含if you wanted to)We would have succeeded. 我們本來是會(huì)成功的。(可能暗含if we had kept trying)Your reputation would be ruined. 你的名譽(yù)會(huì)敗壞的。(可能暗含 if you should accept it)四、例題精析【例題1】【題 干】I must say he reads very well, and I shouldnt be surprised if he_ acting for a living one day. A. had taken up B. takes up C. have taken up D. would have taken up 【答案】B【解析】考查虛擬特殊情況。首先分析句子所給的四個(gè)選項(xiàng)中沒有一個(gè)表示對未來的情況的虛擬的形式should+動(dòng)詞原形，或是were to do，因此可以斷定if引導(dǎo)的條件句在這里最真實(shí)的條件句，用一般現(xiàn)在時(shí)表示一般將來時(shí)，故B正確。 【例題2】【題 干】 Were it not for the snowy weather, we _all right. A. would be B. would have been C. were D. may be 【答案】A【解析】考查條件句表示與現(xiàn)在事實(shí)相反的虛擬，用would、should、could、might+動(dòng)詞原形。【例題3】【題 干】I apologize if I _ you, but I assure you it was unintentional(無意的). A. offend B. had offended C. should have offended D. might have offended 【答案】B【解析】此題要求在if從句中選擇適當(dāng)?shù)膭?dòng)詞形式，以主句中的動(dòng)詞apologize(抱歉)來看，if從句中表達(dá)的內(nèi)容應(yīng)該是過去做的事，因此可以排除A，因?yàn)锳是現(xiàn)在時(shí)。C中should+have+過去分詞結(jié)構(gòu)表示本來應(yīng)該做卻沒有做的事，在此不合題意。D選項(xiàng)中的might+have+過去分詞表示對過去發(fā)生的事情很不肯定的猜測，它表達(dá)的內(nèi)容還不能成為事實(shí)，所以藉此道歉真是不知從何說起，因此此處也不合題意。B選項(xiàng)had offended表示當(dāng)時(shí)已經(jīng)發(fā)生了的動(dòng)作。這是復(fù)雜條件句：apologize 是現(xiàn)在，而條件句是表示對過去假設(shè)的條件句。 【例題4】【題 干】If the Watergate Incident_ Nixon would not have resigned from the presidency. A. did not occur B. had not occurred C. was not occurring D. be circling 【答案】B【解析】had not occurred表示對過去的虛擬，條件句中要用過去完成式，主句中要用should(would, could, might)+動(dòng)