Unit4 Breaking boundaries Using language Grammar 教学设计 -2022-2023学年高中英语外研版（2019）选择性必修第二册

Unit4 Breaking boundaries Using language: Grammar it as an empty subject 教学设计 2 教学目标 学习能力目标：学生能够掌握It作形式主语的相关用法。 文化意识目标：学生能够正确看待疫情，相信国家，相信自己，正确保护自己的健康。 思维品质目标：学生能在学习过程中培养理解与运用等思维品质。 语言能力目标：学生能够在相关句型中灵活使用It作形式主语的用法。 教学重难点 本节微课通过课文中的相关语句导入，再借助疫情的话题带动学生进行学习相关知识点。使学生在学中用，用中学，学用结合。在课堂教学中，条理清晰、层层递进，引导学生逐步突破难点。 教学过程 内 容 时间 1、 导入 Hello, boys and girls. Welcome to my English class. Today we will learn “It as an empty subject”. Firstly, let’s look at these sentences in the textbook: a. It is vital not to take any chances. b. Not to take any chances is vital. c. It is important to remember that Ebola doesn't respect national boundaries. d. to remember that Ebola doesn't respect national boundaries is important. What does “it” refer to in the sentences above? In sentences “a” and “c” respectively refer to “not to take any chances. ” and “to remember that Ebola doesn't respect national boundaries.” “It” is here used as the empty subject instead of the real subject. Do you know why? Because the infinitive structures in the sentences are too long and “It” as the empty subject can make sentences more concise. 今天，我们就一起来学习一下It作形式主语的用法。 45秒 2、 正文讲解 当不定式、动名词或从句在句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，常用it作形式主语置于句首，而将真正的主语放在句尾。此时it只起先行引导作用，本身无词义。 it 充当形式主语，可以替代以下三种情况 : 1. 主语从句 （subject clause） 2. 动词不定式 （infinitive） 3. 动名词 （gerund） · It做形式主语替代主语从句 （1） “It + be + 形容词 + that从句”，可用于此句型的形容词有important、true、clear、obvious、surprising、certain等。需要注意的是，如果形容词是important、essential等词的时候，从句常用 “should + 动词原形”的形式，should可以省略。 It is certain that our country will protect us. During the COVID-19 epidemic, it is important that we (should) wear masks when going out. 2） “It + be + 名词（短语）+ that从句”，可用于此句型的名词有a pity、an honour、a good thing、a surprise、a fact等 It is an honour that medical staff escort our health. It is a fact that good health is more important than anything else. （3） “It + be + 过去分词+ that从句”，可用于此句型的过去分词有believed、hoped、reported、said、shown、announced、expected等； It is reported that the COV