it的基本用法 - 范文无忧网

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1、it的基本用法

（1）用作人称代词，代替前文提到过的事物。 The train has arrived. It arrived half an hour ago. (2)用以代替提示代词this, that。 —What's this？ —It's a knife. —Whose watch is that？ —It's mine. (3)起指示代词的作用，指一个人或事物。 —Who is knocking at the door？ —It's me. (4)指环境情况等。 It was very noisy (quiet) at the very moment. (5)指时间、季节等。

—What time is it？ —It's eight o'clock. It often rains in summer here. (6)指距离。 It is a long way to the school. (7)作形式主语。 It is not easy to finish the work in two days. It is no use crying over spilt milk. It is as pity that you didn't read the book. (8)作形式宾语。 I think it no use arguing with him. I found it very interesting to study English. He made it clear that he was not interested in that subject. (9)用于强调结构。

It was Xiaoming whom(that)I met in the street last night. It was in the street that I met Xiaoming last night. It ws last night that I met Xiaoming in the street. It was I who met Xiaoming in the street last night.

2、含有“It is …”的句型

（1）It is time (for sb.) to do sth. It is (high) time that sb. did sth.（虚拟语气）

（2）It is + 形容词（+of / for sb.）+ to do sth. 通常用 of的词有brave、clever、careful、hopeless、kind、good、naughty、nice、silly、stupid、foolish、wise等。

（3）It is + 形容词 + that + sb. + (should) do sth.（虚拟语气）能用于这个句型的形容词有strange、wonderful、natural、good、proper、right、wrong、well、fortunate、important、necessary、useless、likely、probable、impossible等。有时可省去should而直接用动词原形。如： It is important that we should pay close attention to grain. It is natural that he(should)say so. (4)It is no use/ good + doing sth. It is no use trying again = It is of no use to try again. (5)It is + 被强调部分 + that/who + … Was it in the street that you met her? Who was it that called him“comrade”? It was not until yesterday that I met my old friend. It is in a small factory that my brother is going to work.（注意上述各句均为强调句型的“考点”）比较：It is a small factory where my brother is going to work.（定语从句）

（6）It is said/reported/announced/ (well) known … that…

（7）It is/was + 时间 + since … 从……已多久了。

It is three years since I met him in Beijing. It was a long time since I (had) lived in that small mountain village with these farmers.（注意两句中的时态） It is five months since I arrived in New York.我到纽约已经五个月了。 It is five months since I was in New York.我离开纽约已经五个月了。（注意：终止性动词表示从动作发生时算起；如果是状态动词或持续性动词，则从动作或状态结束时算起。

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（8）It is + 时间 + before … 这个句型和上面句型中时间都是时间段，如long、years、months、weeks、five days、three hours、twenty minutes等。不过主句的时态多用一般将来时或一般过去时。 It will be several years before we meet again. 我们要过好几年才能再见面。 It was not long before they set out for the front. 不久他们就出发去了前线。

（9）It is /was/will be the first/second/third … time that … It is the first time that I have been here. It was the second time that he had seen the film. (10)It is up to sb. to do sth … 应由某人做某事。

It is up to you to decide whether we start or not.