文档介绍：it的用法一、 it作指示代词【完成句子】用 one , ones , it, that , those 填空(1) — I can't find my watch. — You haven't found ______ ? If you want to buy a new ______ , I suggest you buy ______ made in China. (2) We've got a big cup and two small ______. (3) The weight of an elephant is much greater than ______ of a tiger. it one oneones that it指代上文提过的事物/事件时,是同名同物, 相当于 the +名词; one 指代上文提过的单数可数名词是同名异物,相当于 a + 名词;a / an +形容词+ one 等于 a / an +形容词+名词; 复数形式用 ones that 后面常有后置定语,有特指意义,代替不可数名词或单数可数名词,相当于 the +名词(4) The books on the first shelf are easier than ______ on the second shelf. (5) The boy told his story and ______ of the girl upstairs. those/the ones that/the one 复数名词用 those ,相当于 the ones 。【例句观察】— Someone is knocking at the door. Who is it? — It must be Leo. He said he'e to see me. it 指代人时,常指小孩或身份不明的人。【例句观察】 It 's too quiet in the room. Everyone just keeps silent. it 可用以指代环境或情况。【完成例句】根据语境补全句子(6) — What time is it now? — half past seven. (7) — spring now and it's warm these days. It's It is it 可用以指代时间、季节、天气或距离。【注意】 it指代时间时,有如下一些句型: (1) It is time for sth ./ (for sb.)to do sth . / that -从句(should do / did, 必须用虚拟语气) (2) It is / has been + some time + since - 从句(从句用一般过去时) (3) It / This is the first / second … time that -从句(必须使用现在完成时)这是某人第……次做了某事。 It/That was the first/second … time that -从句(必须使用过去完成时) 例: ① It is the second time that she has visited the Great Wall. ② This was the first time that I e late to school. (4) It was +时间点+ when -从句. 例: It was evening when we got home. 例: ①过了 5年他们才从北大毕业。 It was five years before they finally graduated from Beijing University. ②不久,我们就要从我们学校毕业了。 It won't be long before we graduate from our school. (5) It was /will be + some time + before -从句过了/要过多久才……过不了多久就……二、 it作形式主语【完成例句】 (8) is possible for me to make a tour around the world. 【结论】代替由不定式、动名词或从句所表示的真正主语。为平衡句子,通常把不定式作主语改为 it 作形式主语。 It