人教版八年級(jí)英語(yǔ)下冊(cè)《Could you please clean your room?》SectionA PPT教學(xué)課件(第3課時(shí))，共35頁(yè)。
Objectives
To learn to make polite requests and ask permission politely.
To develop your summarizing skills.
To learn new words: pass, borrow, lend, finger, hate, while…
Warming-up
A: Mum, could I go out for dinner with my friends?
B: Sure, that should be OK.
A: Could I get something to drink with my friends after the movie?
B: Sure, you can.
A: Could I get something to drink with my friends after the movie?
B: No, you can’t, you have a basketball game tomorrow.
Grammar Focus
Could I go out for dinner with my friends?
Sure, that should be OK.
Could we get something to drink after the movie?
No, you can’t, you have a basketball game tomorrow.
Could you please take the dog for a walk?
OK, but I want to watch one show first.
Could you please take out the rubbish?
Yes, sure.
情態(tài)動(dòng)詞的語(yǔ)法特征
情態(tài)動(dòng)詞不能單獨(dú)做謂語(yǔ), 除ought和have外, 后面只能接不帶to的不定式。
情態(tài)動(dòng)詞沒(méi)有人稱, 數(shù)的變化, 但有些情態(tài)動(dòng)詞, 如can、will也有一般式和過(guò)去式的變化。
情態(tài)動(dòng)詞的“時(shí)態(tài)”形式并不是時(shí)間區(qū)別的主要標(biāo)志, 不少情況下, 情態(tài)動(dòng)詞的現(xiàn)在式形式和過(guò)去式形式都可用來(lái)表示現(xiàn)在時(shí)間、過(guò)去時(shí)間和將來(lái)時(shí)間。
can 和could：
1) can的主要用法：
A. 表示體力或腦力的能力：
e.g. The girl can dance very well.
B. 表示說(shuō)話的推測(cè)﹑事物的可能性等:
e.g. Can the news be true?
C. 在口語(yǔ)中, can可以表示請(qǐng)求或允許:
e.g. Can I sit here?
can表示“能夠”時(shí)與短語(yǔ)be able to同義，但can只用于一般現(xiàn)在時(shí)或過(guò)去時(shí)，而后者可用于各種時(shí)態(tài)。另外，can表示個(gè)人有某種能力，而be able to表示某人通過(guò)努力、克服困難做成某事，相當(dāng)于succeed in doing sth.；敘述過(guò)去事實(shí)時(shí)，最好用was / were able to，因?yàn)閏ould只表示過(guò)去具有某種能力。
2) could的主要用法：
A. could 是can的過(guò)去式, 表示與過(guò)去有關(guān)的能力和推測(cè):
e.g. We all knew that the young man couldn’t be a doctor.
B. could可以代替can表示請(qǐng)求, 但語(yǔ)氣較can 客氣、委婉:
e.g. Could you lend me your dictionary?
Could I use your bike?
3) can和could接動(dòng)詞的完成形式，表示可能已經(jīng)做某事。can用在否定和疑問(wèn)句中，表示不相信、懷疑等態(tài)度。
e.g. They can’t have gone out because the light is still on.
以could或would提問(wèn)時(shí)，不能再以could或would作答，而應(yīng)該用can或will。如：
—Could I borrow your dictionary?
—Yes, of course you can.
could與can的區(qū)別
could與can都是情態(tài)動(dòng)詞，could是can的過(guò)去式。二者都可用于表示請(qǐng)求，但是用法稍有不同。
can 表示一般性的請(qǐng)求，語(yǔ)氣隨便，常用于熟人之間或長(zhǎng)輩對(duì)晚輩，上級(jí)對(duì)下級(jí)的場(chǎng)合。
e.g. Can you tell us your story,Tony？
托尼，你能給我們講講你的故事嗎？
could表示有禮貌的請(qǐng)求，語(yǔ)氣委婉，常用于非熟人之間或晚輩對(duì)長(zhǎng)輩，下級(jí)對(duì)上級(jí)的場(chǎng)合。比如：
— Could you tell us if it snows in winter in Australia?
— Sure.
— 請(qǐng)告訴我們，澳大利亞冬天下雪嗎?
— 當(dāng)然可以。
have to和must
1. 兩詞都是“必須”的意思，have to 表示客觀的需要，must 表示說(shuō)話人主觀上的看法，即主觀的必要。
My brother was very ill, so I had to call the doctor in the middle of the night.我弟弟病得很厲害，我只得半夜里把醫(yī)生請(qǐng)來(lái)。(客觀需做此事)
He said that they must work hard. 他說(shuō)他們必須努力工作。(主觀上要做這件事)
2. have to 有人稱、數(shù)、時(shí)態(tài)的變化，而must只有一種形式。但must 可用于間接引語(yǔ)中表示過(guò)去的必要或義務(wù)。
He had to look after his sister yesterday.
3. 在否定結(jié)構(gòu)中: don’t have to 表示 “不必”，mustn’t 表示“禁止”。
You don’t have to tell him about it.
你不一定要把此事告訴他。
You mustn’t tell him about it.
你一定不要把這件事告訴他。
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