2015-2016学年高一英语人教版必修3课件：UNIT 2 HEALTHY EATING 5-GRAMMAR .ppt

1、人教课标高一 必修 3Unit 2Find the sentences containing modal verbs in the reading passage.Then usually by lunchtime they would all be sold.What could have happened?Nothing could be better Something terrible must have happened if He could not believe his eyes.Perhaps he should go to the library and find out.

2、He had better do some research!Even though her customers might get thin after eating Yong Huis food They would become tired very quickly.a.should,ought to 都可表示“应该”。ought to 用于表示按道理应当，常指客观的义务或责任，大多数情况下可用should 代替，但比 should 语气重。I should help her because she is in trouble.You ought to take care of the

3、baby.b.表示劝告、建议或命令时，should 和ought to 可通用，但在疑问句中常用should。ought to 的否定式为 oughtnt to 或 ought not to。You should/ought to go to class right away.Should I open the window?What should we do next?c.should,ought to 都可表示推测。He ought to/should be home by now.This is where the oil ought to/should be.should 和 ough

4、t to 后面跟动词不定式的完成式,其肯定句表示“过去应该做而未做”,其否定句则表示“过去不该做但做了”。You should/ought to have made the decision a week ago.I shouldnt have made such a foolish mistake.多数情况下，ought to 可与 should 互换使用。ought to 的反意疑问句用shouldnt 替代。You ought to have helped him with his English,_?A.wont you B.ought not youC.shouldnt youD.w

5、ouldnt you2.must 和 have tomust 的用法1)表示主观的义务和必要,主要用于肯定句和疑问句,意思为“必须，得，要”；由 must 引起的疑问句，肯定回答要用 must 或 have to,否定回答要用neednt 或dont have to,意思是“不必”；must 的否定形式 mustnt 表示禁止，意思是“不能，不许”。如：Must I finish the task right now?我现在必须完成这个工作吗？Yes,you must./Yes,you have to.是的。(No,you neednt./No,you dont have to.不，不必。)Y

6、ou mustnt come here without permission.未经允许，你不能来这儿。have to 的用法1)must 表示一种主观的需要，而 have to 表示一种客观的需要，意思是“不得不”。如：I have to attend an important meeting this afternoon.今天下午我不得不参加一个重要的会议。Mother is out,so I have to look after the shop.妈妈不在家，因此我不得不照看商店。2)have to 的否定形式是 dont have to,相当于 neednt。如：They dont ha

7、ve to buy a computer at present.他们目前没有必要买电脑。The boss has given everyone a special holiday,so we _ go to work tomorrow.A.cant B.mustntC.neednt D.shouldnt【点拨】考查情态动词。根据题意,可知这里表示“没有必要”,故只能选C项。What do you think we can do for our aged parents?You _ do anything except to be with them and be yourself.A.dont

8、 have to B.oughtnt toC.mustnt D.cant【点拨】根据题意“除了和他们呆在一起做你自己外,没有必要做任何事情。”可知这里选择 dont have to 表示“不必”。故选A项。3.must 和 needa.need 作情态动词时,只能用于疑问句和否定句。构成否定句和疑问句时不借助于助动词 do。Need I finish the work today?Yes,you must./No,you neednt.b.must 的肯定形式表示“必须”，否定式表示“禁止、严禁”。You must come here.You mustnt take the book away

9、 from the library.Choose suitable modal verbs below to complete the following dialogues.ought/oughtnt to should/shouldnt willmustnt neednt (dont)have to can/cant1.Sam:How can I grow thinner,Mum?Mum:Well,you _ eat food with plenty of fibre that helps you digest better.And you _ stop drinking cola or

10、eating sweet food.have to should Sam:Does it mean I _ eat my favourite fried chicken any more?Mum:Not exactly,if you love fried chicken,you _ give it up.Just eat it less often.You _ worry too much:a little fried chicken _ do you good!shouldnt needntdont have to/neednt/shouldnt will2.Doctor:You are s

11、ick because youve eaten poisonous mushrooms.Where did you get them?Lucy:I picked them in the forest.I know we _ eat fresh vegetables.Doctor:Oh,but you _ eat them until youre sure they are not poisonous.Lucy:Thank you,doctor.Ill be more careful next time.have tomustnt 3.Charles:I wish I could see thi

12、ngs clearly in the dark.Tom:Eating carrots _ help you see better.You _ eat some every day.ought to shouldmust;oughtnt to;dont have to;couldnt;mustnt;neednt;cant;have to用所给的情态动词填空。1.You _ go on working because you look so tired now.2.The weather turned out to be fine yesterday.I _ have had the troubl

13、e to carry my umbrella with me.oughtnt to/dont have to needntmust;oughtnt to;dont have to;couldnt;mustnt;neednt;cant;have to3.If you earn more than 5,000,you _ pay tax.4.You _ play now!You shall finish your homework first!5.I know things are hard with you,but you _ try to get over the difficulties.have tomustntmust/have tomust;oughtnt to;dont have to;couldnt;mustnt;neednt;cant;have to6.I didnt see her at the meeting this morning;she _ have spoken at the meeting.couldnt/cantHomework Finish Using Structures on Page 50 of Workbook.