人教版(新教材)高中英語選修3Unit2 Healthy Lifestyle精品學(xué)案：Grammar-Infinitives(3) as the subject(步步高)

1、GrammarInfinitives(3) as the subject語法導(dǎo)學(xué)/感悟規(guī)律 重點(diǎn)難點(diǎn)剖析 “、語法感知感知以下課文原句，補(bǔ)全方框下的小題(l)However, during this period, it can be easy for some of them to form bad habits.(2)To prevent harmful habits like these from dominating a teenagers life is essential.(3)To change bad habits is never easy.(4)After all, it

2、is not easy to break bad habits.以上句子中動(dòng)詞不定式都是作主語。.句(1)和句中it作形式主語,真正的主語是后面的動(dòng)詞不定式。語法精析動(dòng)詞不定式作主語一、基本用法動(dòng)詞不定式作主語時(shí)，謂語動(dòng)詞用單數(shù)。To look after these naughty boys is really difficult.照看這些淘氣的男孩真的很難。為了防止頭重腳輕，常用it作形式主語放在句首，作主語的不定式常置于句末。It would be better for you to go there.你還是去那里的好。注意：1.假設(shè)要說明不定式表示的動(dòng)作的發(fā)出者的話，要在不定式前加fo

3、r引起的短語，構(gòu)成for +名詞(或代詞賓格)+不定式”短語，這一短語被稱為不定式的復(fù)合結(jié)構(gòu)。2.在“It is+a的.+不定式復(fù)合結(jié)構(gòu)”句型中，當(dāng)其中的形容詞是說明邏輯主語的性質(zhì)、品 質(zhì)時(shí)，要由of引出邏輯主語，不能用foro這類形容詞主要有clever, foolish, kind, nice, polite, silly, stupid, wise 等。It s easy for him to work out this math problem. 對(duì)他來說解出這道數(shù)學(xué)題很容易。Il was careless of him to make such a mistake.=He was c

4、areless to make such a mistake.出了這樣的錯(cuò)誤，他太粗心了。二、動(dòng)詞不定式和動(dòng)名詞作主語的異同點(diǎn).動(dòng)名詞和不定式作主語的相同點(diǎn)不定式和動(dòng)名詞作主語時(shí)，常常為了保持句子的平衡，用it來作形式主語，如：It is not easy to learn English well.學(xué)好英語不容易。It is no use asking him for help.向他求助是沒有用的。如果主語用了不定式，表語和賓語也要用不定式；主語用了動(dòng)名詞，表語和賓語也要用動(dòng) 名詞，這在英語中稱為對(duì)稱性，如：To see is to believe. = Seeing is believin

5、g.眼見為實(shí)。It is better to stay home than to go out.待在家里比出去要好。.動(dòng)名詞和不定式作主語的不同點(diǎn)不定式作主語常表示具體的某一動(dòng)作；表示泛指或一般的抽象的概念時(shí)，多用動(dòng)名詞。Walking is a good form of exercise for both young and old.散步是一種老幼皆宜的很好的運(yùn)動(dòng)形式。(2)在“It +be+no use(good/help/need) ,之后常用動(dòng)名詞作主語，而少用不定式。It is no use crying over the split milk.覆水難收。It is no help

6、taking this medicine.服用這種藥沒有用。注意：如果該句型中用了 for引出不定式的邏輯主語，就只能用不定式。It is no good for us to do that exercise.我們做那種練習(xí)沒有好處。(3)不定式可以和when, where, how, what, whether等連用，在句子中作主語、賓語和表語, 而動(dòng)名詞那么不能。Where to put the box seems hard to decide.很難決定把這個(gè)箱子放在哪里。Whether to do it hasn t been decided.是否做這件事還沒定下來。達(dá)標(biāo)檢測(cè)I /當(dāng)堂檢

7、測(cè)基礎(chǔ)達(dá)標(biāo)演練;N.單句語法填空It took us about two hours to get(get) there that day.It is no use arguing(argue) with him, for he is so stubborn.It is foolish of you to take a taxi to the town in that situation.It is important for her to prepare(prepare) for the examination.It s our duty to keep(keep) our environm

8、ent clean and tidy.It is no good for you to wait(wait) here for a long time.Whether to hold(hold) a party this weekend hasn t been known yet.The boy was so young that he couldn t decide which one to choose(choose). n.語法填空Advice is a word that is welcomed warmly by a lot of people.lt helps in 9.(achi

9、eve) goals in a better way.As we know, experienced people offer their advice with a positive attitude without making a 10.(judge). You can learn how they give advice.Give advice to people who welcome it.In fact, your focus should be helping others and making them aware that the advice can be useful

10、if 11.(take) in the right spirit.When advice 12.(offer), it should be short. 13. is also essential that while giving advice, one should be fair.As 14.(give) advice is an art, you should always state the positive side first so that the person is 15.(relax) and would in turn welcome your advice.Give a

11、dvice on certain matters.If a friend of yours wants to buy a car and requests your advice on the matter, your aim should be to give him details about things to be purchased, 16. you need not go for some particular brands or items.Similarly, advice on some other important issues, 17. staying in the r

12、elationship or future planning, needs to be given 18.(cautious). 語篇解讀 這是一篇說明文。給人建議是一門藝術(shù)，本文就如何給出建議提出了幾個(gè)注意 事項(xiàng)。K答案UachievingK解析1考查非謂語動(dòng)詞。此處in用作介詞，后接動(dòng)名詞作賓語。K答 案】judg(e)mentK解析力 考查詞性轉(zhuǎn)換。冠詞后接名詞。judg(e)ment 判斷。K 答 案 DtakenK解析考查狀語從句的省略。完整句為：if it is taken in the right spirit o故填taken。K答 案Iis offeredK解析X考查動(dòng)詞的時(shí)態(tài)和語態(tài)。offer與其邏輯主語advice之間為被動(dòng)關(guān)系，由上下文語境可知，文章主體時(shí)態(tài)是一般現(xiàn)在時(shí)，故用一般現(xiàn)在時(shí)的被動(dòng)語態(tài)。K答案HItK解析X句中的it作形式主語，真正的主語為后邊的that從句，首字母大寫。故填I(lǐng)t。K答案XgivingK解析U考查非謂語動(dòng)詞。此處是動(dòng)名詞作主語。K答