Unit 4 Using language 课件 -2023-2024学年高中英语外研版（2019） 选择性必修第二册

unit4 Using language 外研2019版选择性必修第二册 找出下列句子中it的指代内容 1.It was clear enough what she meant. 答案:what she meant 2.It hasn’t been made clear when the new road is to be opened to traffic. 答案:when the new road is to be opened to traffic 3.It is no use asking him. 答案:asking him 新课导入 4.It is bad manners to stare at people. 答案:to stare at people 5.It is up to us to help those in need. 答案:to help those in need 6.It is a mystery to me how it all happened. 答案:how it all happened it作形式主语 it作形式主语时没有具体的意义,只是帮助把真正的主语移到句子后面去,使句子显得平稳一些。it作形式主语时,可以代替三种形式:不定式、动词-ing形式和主语从句。 一、 it代替不定式短语 1.常用于下列句型中: It+be+形容词+(for/of sb.) to do sth. It+be+名词+to do sth. It takes sb.some time to do sth.做……花了某人……时间 It’s up to sb.to do sth.做……是某人的职责或义务 It is everyone’s duty to obey the law. 遵守法律是每个人的义务。 (it作形式主语,代替不定式短语to obey the law) It is difficult for a foreigner to learn Chinese. 对于一个外国人来说,学习汉语是困难的。 (it作形式主语,代替不定式短语to learn Chinese) 二、 it代替动词-ing短语 动词-ing形式作主语用后置形式的情况远不及不定式那么普遍,常限于no good,no use,useless,waste等词的后面。 It is no good/use having a car if you can’t drive. 如果你不会开车,有车也没用。 ( it作形式主语,代替动词-ing短语having a car) It is a waste of time watching TV.看电视是浪费时间。( it作形式主语,代替动词-ing短语watching TV) 2.It be+形容词+for sb.to do sth.与It be+形容词+of sb.to do sth. 如果句型中的形容词描述的是sb.的品质、品格,在逻辑上可以作sb.的表语,则sb.前应用介词of,否则就用for。如: It’s necessary for us to use a short-wave radio to pick up the programmes. 我们用一台短波收音机收听这些节目是必要的。 It was foolish of him to give up the job.(= He was foolish to give up the job.)他放弃那工作是愚蠢的。 三、it代替主语从句 主语从句可以用连词that引导,也可以用连接代词或连接副词引导。如: It was clear that they had no desire for peace. 很清楚他们没有和平的诚意。 (it作形式主语,代替主语从句that they had no desire for peace) It is doubtful whether she will be able to come. 她是否能来还很难说。 (it作形式主语,代替主语从句whether she will be able to come) 四、用it作形式主语,把真正的主语从句移至后面的常见句型 It is a pity/a shame/a fact/an honour/good news/no wonder/a wonder...that...如: It was a pity that the engineer couldn’t come. 可惜工程师没能来。 It is a wonder that he continues to gamble though he always lose