语法学习,含情态动词的被动语态,含情态动词的被动语态,常用的情态动词有：,can, could (能；会), may; might (可以) must(必须), should(应该), would(愿意) have to(必须；不得不), had better(最好做),主动句变被动句的步骤与其它情况相同。,1. We should allow teenagers to watch TV on Sunday.,Teenagers should be allowed to watch TV on Sunday( by us) .,2. My mother can cook delicious meals.Delicious meals can be cooked ( by my mother ).,3. People may catch fish in the river.,Fish may be caught in the river (by people).,4.we must keep teenagers away from the Internet?Teenagers must be kept away from the Internet.,can/couldmustshouldmay/mighthad betterhave to,情态动词+be +过去分词,be done,结构,1.The flowers _often.A. must be water B. must be watered C. must watered D. must water 2. The books may_ for two weeks.A. be kept B. be borrowed C. keep D. borrow 3 The broken bike_ here by Mr Smith.A. can mend B. can mended C. can be mend D. can be mended 4.Young trees should _ every year.A. be planted B. planted C. plant D. are planted,1.Your homework should be finished first. Your homework shouldnt be finished first. Should your homework be finished first ? 2. This magazine can be taken home. This magazine cant be taken home. Can this magazine be taken home ?,3. Trees must be watered every day.Trees mustnt be watered every day.Must trees be watered every day?,情态动词+not + be + 过去分词,can/couldmustshouldmay/mighthad better,not be done,否定式,情态动词+ 主语+ be + 过去分词,Can/CouldMustShouldMay,+ 主语 be done ？,一般疑问式,疑问词+情态动词+ 主语+ be + 过去分词,can/couldmustshouldmay/might,+ 主语 be done ？,疑问词,特殊疑问式,When must this task be finished?这项任务必须在什么时候完成？,含情态动词的被动语态,肯定句: 主语+ 情态动词+ be+ 动词过去分词.否定句: 主语+ 情态动词+ not+ be+动词过去分词.一般疑问句: 情态动词+ 主语+ be+ 动词过去分词?,特殊疑问句：特殊疑问词+ 情态动词+ 主语+ be + 过去分词 ？,4a Rewrite the sentences according to the example. 1. You must clean your bedroom every day.Your bedroom must be cleaned every day. 2. Parents should encourage teenagers to do social work for their community. Teenagers _. 3. Can Lucy do her homework tomorrow instead?Can _?,should be encouraged (by their parents) to do social work for their community,the homework be done (by Lucy) tomorrow instead,n. 社区，社团,4. Do you think we must keep teenagers away from the Internet?Do you think teenagers _? 5. Parents should give teenagers chances to make their own decisions. Teenagers _ _,must be kept away from the Internet,should be given chances to make their own decisions.,keepaway from 避免接近，远离,n. 机会，可能性,自己做决定,Should teenagers _ (ask) to move out when they start working? In many Western countries, teenagers _ (allow) to move out at eighteen. Their parents believe that they should _ (educate) to take care of themselves from a young age. This way, when they _ (start) working they can manage their own lives.,4b Fill in the blanks with the correct forms of the words in brackets.,be asked,are allowed,be educated,start,v. 教育；教导,v. 完成；应付,However, in most Asian societies, it is not common for teenagers to _ (move) out. Chinese parents believe that it is better for children to live with parents who can _ (take) care of them. But the young should then look after their parents as they get older. That is why many Chinese adults _ (continue) to live with their parents.,move,take,continue,n. 社会,Thanks for learning!,Miss Ju,