Unit 2 Section Ⅱ Learning About Language（Word教参）-【优化指导】2024-2025学年新教材高中英语选择性必修第三册（人教版2019）

Section Ⅱ　Learning About Language 动词不定式作主语 [观察] 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 teenager's life is essential. 3．To change bad habits is never easy，even with many attempts. 4．After all，it is not easy to break bad habits. 5．To make choices about myself is within my own power. 6．And if that's true for me，then it might truly be possible to change the world for the better. [探究] 1．句中加黑部分均为动词不定式作主语。 2．句2、3、5的谓语动词都是单数。 3．句1、4、6中加黑部分为句子的真正主语，句中的it为形式主语。 1．思考什么情形下常用动词不定式作主语。 2．思考动词不定式作主语的常见句式结构。 一、动词不定式作主语的概念 [感知] 1．To know something about English is one thing；to know English is quite another. 懂一点英语是一回事；完全掌握英语是另一回事。 2．(2024·新课标 Ⅰ 卷)With the rise of technology it is easy for people to make observations of different species with the aid of a mobile application. 随着技术的兴起，人们很容易借助移动应用程序对不同物种进行观察。 [探究] 1．句1中动词不定式短语直接作主语。 2．句2中It作形式主语，真正的主语(动词不定式短语)后置。 [归纳] 不定式作主语，表示具体的、一次性的或将来的动作；在很多情况下，人们通常用it作为形式上的主语，而把动词不定式移到谓语之后，使句子结构显得平稳一些。 [即练] 单句填空/完成句子/句式升级 ①To_jump(jump) out of the window is dangerous. ②It is important for us to master some basic living skills to prepare us for our future life. ③我很荣幸邀请你来中国。 It_would_be_a_great_honor_for_me to invite you to come to China. ④English is not so easy to learn well. →To_learn_English_well is not so easy.(动词不定式作主语) →It_is_not_so_easy to learn English well.(it 作形式主语) 二、动词不定式作主语的用法 (一)动词不定式直接作主语 [感知] 1．To love and to be loved is the greatest happiness one can get. 爱和被爱是一个人能得到的最大幸福。 2．To get up early is necessary. 早起是必要的。 3．To save time is to lengthen life. 节约时间就是延长生命。 [探究] 1．以上句子中加黑的动词不定式(短语)在句中直接作主语(成分)，谓语动词采用第三人称单数形式。 2．句3的主语是动词不定式短语，作表语的也是动词不定式。 [归纳] 1．动词不定式作主语通常位于句首，表示具体的某次动作，谓语动词采用第三人称单数形式。 2．动词不定式作主语时，若其后需要动词作表语，则作表语的动词也使用不定式形式，即保持形式一致(To do ...is to do ...)。 不定式作主语与动名词作主语的区别 一般来说，动词不定式作主语，表示具体的、一次性的或将来的动作；动名词作主语，表示一般的、泛指的或习惯性的行为。但是在多数情况下无明显区别。如： To see is to believe.＝Seeing is believing. 眼见为实。 [即练] 单句填空/完成句子/一句多译 ①To teach you the uses of the infinitive is(be) my job today. ②To_look(look) after the safety of the community is his responsibility. ③读书不思考，犹如吃饭不消化。 To_read_without_reflecting is like eating without digesting. ④要解决这个恼人的问题是不可能的。 To solve this annoying problem is_out_of_the_question． ⑤寻求帮助是我们能做的最勇敢的举动。 →Asking_for_help is the bravest move we can make. →To_ask_for_help is the bravest move we can make. (二)it作形式主语，动词不定式作真正的主语 [感知] 1．It is interesting to play with snow in winter. 在冬天玩雪很有趣。 2．It's important for us to keep the water clean. 保持水的清洁对我们来说很重要。 3．It's very kind of you to help me. 你能帮助我真是太好了。 4．It must be great fun to fly to the moon in a spaceship. 坐宇宙飞船飞往月球一定很有趣。 [探究] 1．在以上句子中，动词不定式均作主语成分，It放在句首作形式主语。句式结构为“It_is/was＋adj./n.(＋for/of_sb.)＋to_do_sth.”。 2．句3的句式结构是“It is＋adj.＋of_sb.＋to do sth.”，形容词kind描述的是人的特征。 [归纳] 1．it作形式主语时，常用形容词作表语，句式结构为“It is/was＋adj./n.(＋for/of sb.)＋to do sth.”。 2．在“It is/was＋adj.＋for/of sb.to do sth.”结构中，若形容词侧重于评价人物的品质、特征，如kind、good、nice、wise、unwise、clever、silly、stupid、foolish、careless、rude、polite、naughty等，且“sb.”与形容词之间可构成逻辑上的系表关系，则构成动词不定式复合结构的介词应用of；若形容词侧重于描写动词不定式动作的特征，如easy、difficult、comfortable、pleasant、light、heavy、dangerous、interesting 等，则构成动词不定式复合结构的介词应用for。 it作形式主语时，还常用于“It takes/took/will take sb. some time/money to do sth.”句型中。如： It took me more than an hour to do my homework yesterday evening. 昨天晚上我做作业用了一个多小时。 [即练] 单句填空/完成句子 ①It is possible to_walk(walk) or bike the entire 14 kilometers. ②She admits it took her a while to come around to the opinion. ③It is great fun for him to leave for the other city to work. ④根据我们的主观感受来做重要决定是不明智的。 It is not wise to_make_important_decisions_on_the_basis_of_our_subjective_feelings． (三)“特殊疑问词/whether＋动词不定式”作主语 [感知] 1．How to use the computer is a question. 如何使用电脑是一个问题。 2．Where to go has not been decided. 去哪里还没有决定。 3．When to start hasn't been decided yet. 什么时候开始还没有决定。 4．Whether to drive or take a taxi is still a question. 开车去还是乘出租车去还是个问题。 [探究] 1．以上句子的主语都是“特殊疑问词/whether＋动词不定式”形式。 2．以上句子的谓语动词用第三人称单数形式。 [归纳] 动词不定式(短语)可与疑问词when、where、who、what、which、how等及连接副词whether组合，在句中作主语。谓语动词用第三人称单数形式。 [即练] 单句填空/完成句子/句型转换 ①When and where to_cast(cast) a net is more important than how to cast a net. ②会议在哪里举行还不知道。 Where_to_hold_the_meeting is still unknown. ③是否参加接力赛必须由我们的老师来决定。 Whether_to_compete_in_the_relay_race is a decision that has to be made by our teacher. ④How the work should be finished is still a question. →How_to_finish_the_work is still a question. 用所给动词的适当形式填空 As is often heard，some young people consider life 1.to_be(be) unfair and think that it is hard 2.to_lead(lead) a happy life.In response to this opinion，I'd like to say，“It is a good idea 3.to_change(change) it for the better if you're not fond of your life.” It is beneficial to your life 4.to_do(do) the following things well. The first thing for you is 5.to_forgive(forgive) mistakes made by others.We humans are making mistakes all the way.So it is necessary 6.to_accept(accept) what you or others have done wrong and try 7.to_do(do) better next time.In fact，it is the only way 8.to_correct(correct) mistakes so as to make the mistakes disappear. 9．To_clean(clean) up your house is also important.Indeed it's very good 10.for you to make the house where you work and live really enjoyable. [课时梯级训练(六)见P132] 学科网（北京）股份有限公司 $$