it用法二

it用作形式主语或形式宾语的用法

1. it用作形式主语

当不定式、动名词、从句等用作主语时，为避免头重脚轻，通常在句首使用形式主语it，而把真正的主语放在句子末尾。如：
It’s a pity to refuse. 拒绝是令人遗憾的。
It’s no use saying any more about it. 再谈这事没有用。
It’s not known where she went. 她到哪里去了没人知道。
注：It is said / reported / believed / understood that… 这类结构中的 it 也是形式主语。如：
It’s reported that two people were injured in the accident. 据报导这次事故中有两人受伤。

2. it用作形式宾语

当不定式、动名词、从句等用作宾语且其后跟有宾语补足语时，就应在宾语补足语前使用形式宾语，而将真正的宾语移至句末。如：
I find it easy to get on with her. 我发现她很容易相处。
I think it best that you should stay here. 我认为你最好住这儿。
They haven’t made it known where they are to hold the conference. 他们还没宣布会议在哪里开。

几种特殊的形式宾语it

1. enjoy, like, dislike, love, hate, prefer, appreciate等动词后接 if 从句或 when 从句，通常应先在动词后接 it 作形式宾语。如：
She won’t like it if you arrive late. 她不喜欢你迟到。
He hates it when people use his bike. 他讨厌别人用他的自行车。
I hate it if you say such things in public. 我讨厌你在大庭广众之下说那样的事。
I’d prefer it if I didn’t have to do so much work. 要是我不必做那么多工作，那就太好了。
I would appreciate it very much if you would help me with it. 如果你能帮助我做这事，我会十分感激。