1、语法精讲语法精讲Unit 2 The Infinitive (to do )不定式的时态和语态不定式的时态和语态不 定 式 主 动 被 动 一 般 to write to be written 进 行 to be writing 完 成 to have written to have been written 完成进行 to have been writing 4. It is important _ Tom to get that job. It is kind _ you to help me with my homework. 1. _( talk ) with him is a gre
2、at pleasure. 2. _( help ) others is our duty.To talkTo helpIt is our duty to help othersforof3.It is easy_ _ (学生读)for the students to read.Look at the following sentences and pay attention to the italicised infinitives. Find more infinitives in the reading passage. In pairs, discuss their meanings a
3、nd functions.1 To change bad habits is never easy.2 It took the surgeon (n.外科医生外科医生) three hours to finish my mothers lung surgery (n. 外科手术外科手术).主语主语主语主语3 To join the Peoples Liberation (n. 解放解放) Army , it is required for men to shave off (剃掉剃掉,刮掉刮掉) their beards.4 It was not polite to disturb(v. 打扰
4、打扰)your neighbours with loud music last night.目的状语目的状语主语主语主语主语More sentences in the reading passage:1. 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 neve
5、r easy, even with many attempts.4. After all, it is not easy to break bad habits.动词不定式作主语常见的三种形式动词不定式作主语常见的三种形式1. 不定式作主语不定式作主语通常通常位于句首位于句首，表示具体的某次动作，表示具体的某次动作，谓谓语动词用单数语动词用单数。 e.g. To see is to believe. 百闻不如一见。百闻不如一见。 To get up early is necessary. 早起是必要的。早起是必要的。To learn a skill is very important for
6、everyone in society.学习一项技能对社会上的每个人都很重要。学习一项技能对社会上的每个人都很重要。To finish the building in a month is difficult. 要在一个月内完成这座建筑是困难的。要在一个月内完成这座建筑是困难的。2. 动词不定式与动词不定式与疑问词疑问词who, whom, whose, what, which, when, where, how等等连用构成不定式短语，也可作主语。连用构成不定式短语，也可作主语。 e.g. How to use the computer is the question.如何使用计算机是个问题。
7、如何使用计算机是个问题。 Where to go has not been decided. 去哪儿还没有定下来。去哪儿还没有定下来。 3. 当主语较长，谓语较短时，常用当主语较长，谓语较短时，常用it作形式主语作形式主语放在句放在句首，而将真正的主语首，而将真正的主语不定式放到谓语的后面不定式放到谓语的后面。e.g. Its not easy to work out the problem. = To work out the problem is not easy.计算出这道题不容易。计算出这道题不容易。It is interesting to play with snow in wint
8、er. 冬季里玩雪是很有趣的。冬季里玩雪是很有趣的。It is terrible to see the ship sinking into the sea. 目睹目睹轮船沉入大海，真是太可怕了。轮船沉入大海，真是太可怕了。it作形式主语代替真正主语不定式常见于以下情况中：作形式主语代替真正主语不定式常见于以下情况中：It is + adj. + for/of sb. to do sth.It is + n. + (for sb.) to do sth.It takes/took/will take sb. some time/money to do sth.【温馨提示温馨提示】常用于表示事物的
9、特征，用于常用于表示事物的特征，用于此句型的形容词有：此句型的形容词有：easy,hard,difficult,possible,important,impossible,necessary,good,bad,exciting,interesting,surprising等。等。1) It is adj. for sb. to do sth.sb. 是是to do sth.的逻辑主语的逻辑主语It is +adj.+ for/of sb. to do sth.e.g. It is necessary for young students to learn aforeign language.
10、对对年轻的学生来说，学习一门外语是必要的。年轻的学生来说，学习一门外语是必要的。It is necessary for you to change your job. 你你有必要换工作。有必要换工作。It was impossible for them to complete the task in such a short time. 他们他们不可能在这么短的时间内完成这项任务。不可能在这么短的时间内完成这项任务。Its important for us to keep the water clean. 保持保持水质清洁对我们来说是很重要的。水质清洁对我们来说是很重要的。常见的此类形容词有：
11、常见的此类形容词有：kind,nice,wise,silly,polite,impolite,friendly,foolish,clever等。等。2) It isadj.of sb.to do sth. 形容词用来表示不定式的逻辑形容词用来表示不定式的逻辑主语主语(sb.)的的性质、特征或品德性质、特征或品德e.g. It was silly of you to give up such a good chance！ 你你放弃这么好的一个机会，真傻放弃这么好的一个机会，真傻!Its very kind of you to say so. 你你这样说真是太好了。这样说真是太好了。 It is
12、friendly of the family to try to make me feel at home in their house. 这这家人对我很友好，使我在他们家里感到宾至如归。家人对我很友好，使我在他们家里感到宾至如归。It was rude of the boy to jump the queue! 那个那个男孩插队真是太无礼了男孩插队真是太无礼了!常见的名词有：常见的名词有：pity,shame,pleasure,ones duty,ones job,fun,joy,good manners,bad manners等。等。It is + n. + (for sb.) to do
13、 sth.e.g. What a pity it is for you to have missed such a wonderful film. 真遗憾你错过了这样一个精彩的电影。真遗憾你错过了这样一个精彩的电影。 It must be great fun to fly to the moon in a spaceship. 乘乘宇宙飞船飞往月球一定很有趣。宇宙飞船飞往月球一定很有趣。 It takes/took/will take sb. some time/money to do sth. 做做某事花费某人多长某事花费某人多长时间时间(钱钱)e.g.It took me more tha
14、n an hour to do my homework yesterday evening. 昨天晚上昨天晚上我做作业用了一个多小时。我做作业用了一个多小时。 It will take us a lot of money to buy that house. 买买那套房子要花费我们很多钱。那套房子要花费我们很多钱。 3. 如果要说明不定式表示的动作是谁做的，如果要说明不定式表示的动作是谁做的，可以在不定式前加一个由可以在不定式前加一个由 for/of for/of 引起的短语引起的短语, ,构成构成_。2. 不定式作主语时不定式作主语时,可以用可以用it作作_.4.It is+adj+for
15、sb to do 5. It is+adj+ of sb to do(adj: kind, good, nice, wise, unwise, clever, silly, stupid, foolish, careless, rude, polite, naughty)（修饰（修饰人品人品形容词）形容词）（修饰物的形容词）（修饰物的形容词）1.单个不定式作主语，谓语动词单个不定式作主语，谓语动词_单数单数形式主语形式主语不定式的复合结构不定式的复合结构(adj.: easy ,difficult, comfortable, pleasant, light , dangerous， tires
16、ome, interesting , heavy, fit)Join the words to make full sentences, and then join the sentences to make a paragraph. You can add your own sentences if necessary to make your paragraph more meaningful. 1. important / avoid / passive cigarette smoking It is important to avoid passive cigarette smokin
17、g. n. 香烟香烟2. will take / nutrition specialist / a balanced diet menu / make / an hour / for youIt will take the nutrition specialist an hour to make a balanced diet for you.3. useful / turn to / fitness consultant / for adviceIt is useful to turn to the fitness consultant foradvice.n. 专家专家n. 顾问顾问4.
18、illegal / dangerous / take drugs5. harmful / skip breakfast / oftenIt is illegal and dangerous to take drugs.It is harmful to skip breakfast often.n. 毒品，药品毒品，药品v. 跳过跳过Complete the conversations with the correct forms of the phrases in the box.1. A: Hello, doctor. I want to lose weight, but I just ca
19、nt seem to do it. What can you do to help me?B: Well, first, its necessary to _ what you eat. Cut out all fatty food and sugary drinks, and eat more fruit and vegetables.be in control ofbegin with, be in control of, make a choice, decide on, make up ones mind2. A: I really need to _ a way to exercis
20、e more. I could use a fitness app, but my phones full.B: So delete a few files. Im sure the app doesnt take up much space.3. A: Before exercising, always do a few warm-ups to _.B: I know. But then I always feel too tired to continue!decide onbegin withbegin with, be in control of, make a choice, dec
21、ide on, make up ones mind4. A: Should I go for the pizza or the fried chicken? I hate _ like these. You know what Im going to eat both!B: Wow! Dont eat too much junk food youll get fat, Ive actually _ to go on a diet, so Ill just stick to the fruit salad.making choicesmade up my mindbegin with, be in control of, make a choice, decide on, make up ones mind谢谢观看谢谢观看Unit 2
