“情态动词+have_done”结构用法小结解析.ppt

Add your company slogan 情态动词用法归纳 情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语 Should / ought to dare /need 情态动词+have done 用法总结 1) should, ought to表示“应该”，ought to表示义务或责任，比should语气重。 1. I should help her because she is in trouble. 2. You ought to take care of the baby. 2) 表示劝告、建议和命令。should, ought to可通用，但在疑问句中常用should。 1. You should / ought to go to class right away. 2. Should I open the window? should, ought to 3) 表示推测 should , ought to (客观推测), must(主观推测)。 1.He must be home by now. (断定他已到家) 2.He ought to/should be home by now.(不太肯定) 3. This is where the oil must be.(直爽) 4. This is where the oil ought to/should be.(含蓄) should, ought to dare, need 1) dare作情态动词用时, 常用于疑问句、否定句和条件从句中, 过去式形式为dared。 1． How dare you say I’m unfair? 2． He daren’t speak English before such a crowd, dare he? 3． If we dared not go there that day， we couldn’t get the beautiful flowers. 2) need 作情态动词用时, 常用于疑问句、否定句。在肯定句中一般用must, have to, ought to, should代替。 1．You needn’t come so early. 2. ---- Need I finish the work today? ---- Yes, you must. / No, you needn’t. dare, need 3) dare和 need作实义动词用时， 有人称、时态和数的变化。在肯定句中，dare后面常接带to的不定式。在疑问句和否定句中，dare后面可接带to或不带to的不定式。而need后面只能接带to的不定式。 1. I dare to swim across this river. 2. He doesn’t dare (to) answer. 3. He needs to finish his homework today. “情态动词+have done”结构用法小结 “情态动词+have done”结构用法小结 课文原句： 1. tell him/her that he/she should have studied,… 2. Frederick William Ⅰ, the king of Prussia, could never have imagined that his greatest gift to the Russian people would have such an amazing history. 重庆市垫江中学 周洋 “情态动词+have done”结构用法小结 考题感知： 1. She ___ have left school. For her bike is still here.(天津·６) A. can’t B. wouldn’t C. shouldn’t D. needn’t “情态动词+have done”结构用法小结 2. –I can’t find my purse anywhere. –You ___ have lost it while shoping.(重庆·３０) A. may B. can C. should D. would “情态动词+have done”结构用法小结 3. What a pity! Considering his ability and experience, he ___ better.(江西·２６) A.