當不定式、動名詞、從句等複雜成分用作賓語且其後跟有賓語補足語時，通常會在賓語補足語前使用形式賓語it，而將真正的賓語移至句末，其基本結構為「動詞+it+賓語補足語+不定式(動名詞或從句)」。如：
I find it difficult to do the job well.
我發現做好這件事不容易。
I think it best that you should stay here.
我認為你最好住這兒。
We think it no use complaining.
我們認為抱怨是沒有用的。
但是，以下幾種形式賓語比較特殊，同學們需引起注意(同時它們也是高考的常考考點)：
1. 動詞+ it + that-從句。如：
I like it that you came. 你來了，我很高興。
I take it (that) he will come on time. 我認為他會準時來的。
You can put it that it was arranged before. 你可以說這是以前安排的。
Rumor has it that the defence minister will soon resign.
據傳聞，國防部長不久就要辭職。
說明：能用於此結構的動詞不多，常見的有 have, take, put, like 等。
2. 動詞 + it + when (if)-從句。如：
I dislike it when you whistle. 我不愛聽你吹口哨。
We really appreciate it when she offered to help. 她來幫忙了，我們十分感激。
I'd prefer it if I didn't have to do so much work.
要是我不必做那麼多工作，好就太好了。
說明：能用於此結構的動詞不多，常見的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。
3. 動詞 + prep + it + that-從句。如：
See to it that you're not late again. 注意千萬不要再遲到。
Look to it that this doesn't happen again. 注意不要再發生這種事。
I can't answer for it that he will come. 我不能保證他會來。
You may rely on it that he'll come to meet you. 你放心，他會來接你的。
說明：能用於此結構的動詞不多，常見的有see to, look to, insist on, stick to, depend on, answer for 等。
4. 動詞 + it + 介詞短語+ that-從句。如：
I owe it to you that I am still alive. 多虧有你我才仍然活著。
I took it for granted that he would help us. 我認為他會幫助我們的。
說明：能用於此結構的動詞不多，常見的有take it for granted, bring it to sb's attention, owe it to sb 等。