高中英語知識(shí)點(diǎn)大全31：can、may、must表推測(cè)的用法

1、高中英語知識(shí)點(diǎn)大全（31）：can/may/must表推測(cè)的用法1、can/may/must表推測(cè)的用法can, may, must等都可用于表推測(cè)，但它們的含義和用法不同。must語氣最肯定，指“一定、必定”，只用于肯定句中。“must+動(dòng)詞原形”表示對(duì)現(xiàn)在情況的推測(cè)；“must + have + done ”表示對(duì)過去情況的推測(cè)。如：Mum must be cooking supper now.媽媽現(xiàn)在一定在做晚飯。He must have finished his work.他一定完成他的工作了。May/might 表示“或許，可能”。如：Tom may go abroad n

2、ext year.湯姆明年可能要出國(guó)。She might have finished the work.她可能已完成這項(xiàng)工作了。He cant know the answer.他不可能知道這個(gè)答案。can/could 表示“可能，會(huì)”，我用于否定和疑問句中。如：Could she he at home?她可能在家嗎？can,表示一時(shí)的情況，意為“有時(shí)侯會(huì)”。can的這種用法，只用在肯定句中。如：Children are lovely, but they can be tiring.Training by yourself in a game can be highly dangerous.2、

3、case 用法小結(jié)(1)名詞case的詞意意為“情形、情況”。If thats the case, youll have to work much harder.如果是那種情形的話，你將不得不更加努力地工作。意為“病例、案例”。There were seven cases of cholera.有7起霍亂的病例。The civil case will be heard in court next week. 這一案件將于下星期審理。意為“箱、盒、容器”。John bought a case of beer.約翰買了一箱啤酒。(2)由case構(gòu)成的短語in case 意為“因?yàn)榭赡馨l(fā)生

4、某事、以防萬一”，是介詞短語，在句中作狀語，常可置于句尾；也可用做連詞，后跟that從句(that常省略)，表示條件或目的，從句謂語習(xí)慣用should+動(dòng)詞原形(should常省略)或陳述語氣。It may rainyoud better take an umbrella(just)in case(it does).可能下雨你最好帶把雨傘，以防萬一。In case(=If)he arrives before I get back, please ask him to wait.如果他在我回來之前到，請(qǐng)讓他等一下。He doesnt dare to leave the house in case

5、(that)he should be recognized.他不敢出門，生怕被認(rèn)出來。in that case 意為“既然那樣、假若是那樣的話”，用來承接上文。In that case, you wouldnt have a pan on fire. Youd have a house on fire！要是那樣，你就不光使鍋著火，你還會(huì)把房子燒起來。You dont like the job? In that case why dont you leave?你不喜歡這份工作？那你怎么不辭掉呢？He may be late. In that case we ought to wait

6、for him.他可能遲到，因此我們應(yīng)該等他。in any case 意為“無論如何、總之”。We have to help him to pay the debt in case.我們無論如何要幫他還債。in no case 意為“在任何情形下決不、無論如何都不”，用于句首時(shí)句子要進(jìn)行部分倒裝。In no case shall I forget the expression on her face.我決不會(huì)忘記她臉上的表情。in case of sth. 意為“若發(fā)生某事、如果、假如”，是短語介詞，后接名詞、代詞、-ing形式作賓語。In case of fire, ring th

7、e alarm bell.遇火警時(shí)立即按警鈴。In case of rain（=In case it rains）,they cant go.要是下雨，他們就走不了了。In case of his being absent, well put off the meeting till next week.如果他缺席，我們就會(huì)把會(huì)議推遲到下周。in the case of 意為“至于、就來說”，是短語介詞。In the case of your debt, Ill pay it off for you.至于你的欠款，我會(huì)替你還清的。3、catch fire/ on firecatch fire 意為“著火”，表示動(dòng)作。on fire 意為“著火、在燃燒”，表示狀態(tài)。如：Suddenly a pan of