it用作形式宾语的用法
一、基本用法
当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语it，而将真正的宾语移至句末，其基本结构为“动词+it+宾语补足语+不定式(动名词或从句)”：
I find it difficult to do the job well. 我发现做好这件事不容易。
I think it best that you should stay here. 我认为你最好住这儿。
We think it no use complaining. 我们认为抱怨是没有用的。
二、几种特殊的形式宾语
通常意义的形式宾语主要见于真正宾语为不定式、动名词、从句等且其后跟有宾语补足语时的情形，即用于“动词+it+宾语补足语+真正的宾语”这样的结构，但以下几类形式宾语却比较特殊，其后没有宾语补足语。
1. 动词+ it + that-从句
I like it that you came. 你来了，我很高兴。
I take it (that) he will come on time. 我认为他会准时来的。
You can put it that it was arranged before. 你可以说这是以前安排的。
Rumor has it that the defence minister will soon resign. 据传闻，国防部长不久就要辞职。
【注】能用于此结构的动词不多，常见的有 have, take, put, like 等。
2. 动词 + it + when (if)-从句
I dislike it when you whistle. 我不爱听你吹口哨。
We really appreciate it when she offered to help. 她来帮忙了，我们十分感激。
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，好就太好了。
【注】能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。it用作形式宾语的用法
一、基本用法
当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语it，而将真正的宾语移至句末，其基本结构为“动词+it+宾语补足语+不定式(动名词或从句)”：
I find it difficult to do the job well. 我发现做好这件事不容易。
I think it best that you should stay here. 我认为你最好住这儿。
We think it no use complaining. 我们认为抱怨是没有用的。
二、几种特殊的形式宾语
通常意义的形式宾语主要见于真正宾语为不定式、动名词、从句等且其后跟有宾语补足语时的情形，即用于“动词+it+宾语补足语+真正的宾语”这样的结构，但以下几类形式宾语却比较特殊，其后没有宾语补足语。
1. 动词+ it + that-从句
I like it that you came. 你来了，我很高兴。
I take it (that) he will come on time. 我认为他会准时来的。
You can put it that it was arranged before. 你可以说这是以前安排的。
Rumor has it that the defence minister will soon resign. 据传闻，国防部长不久就要辞职。
【注】能用于此结构的动词不多，常见的有 have, take, put, like 等。
2. 动词 + it + when (if)-从句
I dislike it when you whistle. 我不爱听你吹口哨。
We really appreciate it when she offered to help. 她来帮忙了，我们十分感激。
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，好就太好了。
【注】能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。
固定用法如下：
1. 动词+it+宾语补足语+不定式。当不定式、动名词、从句等复杂成分用作宾语且后面跟有宾语补足语时，通常会在宾语补足语前使用it作形式宾语，而将真正的宾语移至句末。
2. 动词+it+that从句。
3. 动词+it+when/if从句。
4. 动词+prep.+it+that从句。
5. 动词+it+介词短语+that从句。
6. It+be+被强调部分+that/who+其他部分。这是强调句的基本结构。
例句：
1、It was a computer that he bought last week.
2、I took it for granted that he would help us.
3、We really appreciate it when she offered to help.
4、I find it difficult to do the job well.
5、I think it best that you should stay there.