【正文】 t out, I shall knock you down. (警告)用于第二、第三人稱。 情態(tài)動(dòng)詞意義 例句 備注 will/would表示意愿 ①I will do everything for you. ②None is so blind as those who won39。t see. 表請求 Will/ Would you please close the window？ 用于疑問句中。would更委婉 表示某種傾向或習(xí)慣性動(dòng)作 ①Fish will die without water. ②Every time she was in trouble，she would turn to him for help. (would指過去某一段時(shí)間的情況，常與表示過去的時(shí)間狀語連用，意為“總是，總會”，后面只能接動(dòng)作性的動(dòng)詞。) used to表示與現(xiàn)在的情況相反，表示“過去如此而現(xiàn)在不再這樣”。其后既可接表動(dòng)作的動(dòng)詞，也可接表狀態(tài)的動(dòng)詞。如：There used to be an apple tree in front of the house.情態(tài)動(dòng)詞意義 例句 備注 will/would表示功能(能，行) ①If you don39。t have a pen, a pencil will do.②We tried the door again，but it wouldn39。t open. 與否定詞連用常表示“拒絕”。 表示推測(可能、大概) ①This will be the house you are looking for. ②I would be about ten when my father left home.二、 情態(tài)動(dòng)詞＋have done 情態(tài)動(dòng)詞意義 例句 備注 must have done；may/might have done；can/could have done一定(肯定句)；可能(肯定句和否定句)；可能(疑問句和否定句)You can39。t/couldn39。t have met my grandmother. She died before you were born. 對過去的事情的推測 might have done。 couldhave done；would have done本來可能做……而未做；本可以做……而未做；本來會做……而未做①He might have given you more help, even though he was very busy.②We could have walked there, and it was so near.與過去事實(shí)相反的虛擬表達(dá) 情態(tài)動(dòng)詞意義 例句 備注 should/ought to have done本應(yīng)該做……而未做 Your brother has failed English exam again. You ought to have given him more help. 表示責(zé)備needn39。t have done本不需要做……但卻做了You needn39。t have wakened me up。 I don39。t have to go to work today.四、虛擬語氣 虛擬語氣表示說話人所說的話不是事實(shí)，而是一種假設(shè)、愿望、懷疑或推測。1． 虛擬語氣在條件句中的用法 　if從句主句與現(xiàn)在事實(shí)相反if＋主語＋動(dòng)詞過去式主語＋should/would/could/might＋動(dòng)詞原形與過去事實(shí)相反If ＋主語＋had＋過去分詞主語＋should/would/could/might＋ have＋ 過去分詞與將來事實(shí)相反(1) if＋主語＋動(dòng)詞過去式主語＋should/would/could/ might＋動(dòng)詞原形(2)if＋主語＋were to＋動(dòng)詞原形(3) if＋主語＋should＋動(dòng)詞原形If it were to rain tomorrow, I should not drive my car. 如果明天下雨的話，我就不開車了。(明天的情況還不知道) If I had done it in time, I should have had a good time. 如果我及時(shí)做的話，日子就好過多了。(可惜當(dāng)時(shí)沒能及時(shí)做) 注意：(1) 主句中的should通常用于第一人稱，would可用于任何人稱。(2) 條件句中如果動(dòng)詞是be，其過去式所有人稱的單復(fù)數(shù)都可用were；在第一、三人稱單數(shù)的口語中，可用was代替were。但在if I were you中，不能說成if I was you。(3) 當(dāng)條件從句的行為與主句所表示的行為所發(fā)生的時(shí)間不一致時(shí)，主從句中動(dòng)詞的形式要根據(jù)它所標(biāo)示的時(shí)間作出相應(yīng)的調(diào)整，這就是所謂的“錯(cuò)綜條件虛擬語氣”。如： If they had studied hard, they could do it easily now. 如果他們以前努力學(xué)習(xí)的話，現(xiàn)在干得就會容易些了。 If he had not taken my advice, he wouldn39。t do it much better like this. 如果他不聽我的建議，他就不會干得這么好了。(4) 在條件句中，如果有were, had, should等，則可省略if，但應(yīng)注意把were, had, should等提到從句主語之前。如：If he were to e, I would join him in the discussion. ＝ Were he to e, I would join him in the discussion. 如果他來，我將和他一道參加討論。(5) 有些虛擬條件句沒有從句，虛擬條件句是通過上下文或介詞短語表示出來的。如： But for air and water, there would be no life on the earth. 要是沒有空氣和水，地球上就沒有生命。(介詞短語but for提供了虛擬條件) With your help, we might finish the plan earlier. 要是有你的幫助，我們就可以早些完成任務(wù)。(介詞短語with your help充當(dāng)虛擬條件句)2． 虛擬語氣在wish從句中的用法專題八 │ 正面解讀　賓語從句愿望I wish　　主語＋動(dòng)詞過去式現(xiàn)在不能實(shí)現(xiàn)的愿望主語＋had＋過去分詞過去不能實(shí)現(xiàn)的愿望主語＋would/might＋動(dòng)詞原形將來不能實(shí)現(xiàn)的愿望I wish I were a doctor. 我希望我是個(gè)醫(yī)生就好了。(現(xiàn)在) I wish that the rain would stop. 我希望雨能停下來。(將來) I wish that he had not made so much fuss about it. 我希望他不要把事情搞大了。(過去)3． 虛擬語氣在名詞性從句中的使用(1) 在insist；mand，order；demand，request，require，desire；advise, propose, suggest，remend等表示“命令、要求、建議”的動(dòng)詞后接的賓語從句中要使用虛擬語氣。如： He suggests that she (should) leave the house at once. 他要她立刻離開這所房子。He proposed that we (should) deal with the problem by the view of development. 他建議我們應(yīng)該用發(fā)展的眼光處理這個(gè)問題。(2) 與上述動(dòng)詞相對應(yīng)的名詞suggestion, order, demand , proposal 等后的表語從句、同位語從句中也要使用虛擬語氣(should可省略)。如： My proposal is that we (should) set a deadline for handing in the plan. 我的建議是為這個(gè)計(jì)劃設(shè)定一個(gè)上交的期限。(3) 在It be suggested (ordered, demanded, proposed, … )that… 結(jié)構(gòu)中，主語從句中也要使用虛擬語氣。如： It39。s required that every student be on time for school. 要求每個(gè)學(xué)生準(zhǔn)時(shí)到校。(4) 在do you suggest/remend用在特殊疑問句中作插入語時(shí)，句子的動(dòng)詞也使用虛擬語氣，即“should＋動(dòng)詞原形”的形式，其中should可以省略。如： What type of puter do you remend/ suggest we (should) buy? 你建議我們買什么類型的電腦呢？(5) 在It39。s＋necessary，essential，important, strange, natural等形容詞＋ that從句或It39。s a pity，a shame等名詞＋ that 從句中，謂語動(dòng)詞可以使用should do。如： It is necessary that the badly wounded man should be treated immediately. 這位重傷員必須馬上治療。 It39。s a pity that you should be so careless. 你竟然如此粗心，真是可惜。4． 虛擬語氣在狀語從句中的用法 在as if/though引導(dǎo)的狀語從句中，謂語動(dòng)詞用過去式表示與現(xiàn)在相反的情況；用過去完成式，表示與過去相反的情況等。其變化與wish后的賓語從句的變化相同。如： I39。ve loved you as if you were my relative. 我一直愛你仿佛你是我的親人。5． 虛擬語氣在其他一些句型中的用法(1) It39。s high time that173。從句中，謂語動(dòng)詞可以使用過去式，也可使用should＋動(dòng)詞原形；表示“早該……了”，其中should不可省略。如： It39。s high time we got up/should get up. 我們早該起床了。(2) would rather＋從句中，謂語動(dòng)詞用過去式表示與現(xiàn)在或?qū)淼那闆r相反；用過去完成式，表示與過去的情況相反。如： I would rather you came tomorrow. 我寧愿你明天來。(3) if only…要是……多好啊。如： If only you hadn39。t offended him. 你當(dāng)時(shí)不惹他就好了。 If only he could e tomorrow. 他明天能來就好了。(4) 其他一些表示祝愿的句型。如： May you succeed