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)”。如：

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。

但是，以下几种形式宾语比较特殊，同学们需引起注意（同时它们也是高考的常考考点）：

1. 动词+ it + that-从句。如：

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。

说明：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。如：

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。

说明：能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。

3. 动词 + prep + it + that-从句。如：

See to it that you're not late again. 注意千万不要再迟到。

Look to it that this doesn't happen again. 注意不要再发生这种事。

I can't answer for it that he will come. 我不能保证他会来。

You may rely on it that he'll come to meet you. 你放心，他会来接你的。

说明：能用于此结构的动词不多，常见的有see to, look to, insist on, stick to, depend on, answer for 等。

4. 动词 + it + 介词短语+ that-从句。如：

I owe it to you that I am still alive. 多亏有你我才仍然活着。

I took it for granted that he would help us. 我认为他会帮助我们的。

说明：能用于此结构的动词不多，常见的有take it for granted, bring it to sb's attention, owe it to sb 等。