高三英语备讲和必备语法Grammar： it 的用法.pptxVIP

it 的用法 ; it 的用法 学习提纲： （一） （二） （三）;（一）代词 it 1. 用作人称代词，代替前文提到过的事物。 ① Where is the key? --- It is in my pocket. ② The sun has risen. It shines brightly. ③ We’re going to hold a meeting tomorrow afternoon. Please tell Mr. Wang about it. ;2. 用作指示代词，起着this或that的作用。 ① What’s this? --- It is an electronic computer. ② What’s that? --- It’s a colour television (set). ③ Who is it? --- It’s me. ④ Who’s on the telephone? --- It???s Mary.;3. 用作无人称代词，指时间、自然现象 （天气、气候、明暗等）、距离、量度价 值等。 ① What time is it now? --- It’s half past ten. ② It’s time for the meeting. ③ What day is it today? --- It’s Saturday. ④ What’s the date today? --- It is May 14, 1984.;⑤ What’s the weather like today? --- It’s fine. ⑥ It is snowing. ⑦ It’s getting dark. ⑧ It is three miles to the railway station. ⑨ What’s the cost? --- It’s twenty dollars.;（二）引导词 it 1. it 作形式主语 当主语是不定式、动名词或从句时，常用it作形式上的主语，而把真正的主语放在句子的后部。 1) it 代替不定式短语 It is everyone’s duty to obey the law. = To obey the law is everyone’s duty.;1) it 代替不定式短语 ① It is everyone’s duty to obey the law. ② It is not right to use these places as rubbish dumps. ③ It is difficult for a foreigner to learn Chinese. ④ It requires courage to do this kind of work.;2) it 代替动名词短语 ① It is no use asking him. (=It is no use to ask him.) ② It’s no good talking to him. ③ It’s dangerous skating on thin ice. ④ It won’t be any help my going with you.;3) it 代替从句 ① It is strange that nobody knows where he has gone. ② It is said that maths is the most important of all the sciences. ③ Has it been decided when we are to hold the sports meet? ④ It seems that this pen writes more smoothly.;2. it 作形式宾语 当宾语是不定式短语、动名词短语或 从句时，如果其后有宾语补足语，则必须 用 it 作形式宾语，将真正的宾语放在宾语 补足语后面。如： ① Tom