宾语从句可以分为三类

(1).动词的宾语从句

1.1 大多数位于动词后面

Eg：I hope you can join us in the game.

1.2 有些是“动词+副词”后

Find out / point out / figure out / turn out/ figure out

Eg： Can you figure out what the poet really means in this poem?

1.3 有些动词短语后面

Make sure / make up one’s mind / keep in mind

Eg; we should keep in mind that sports can be a great boost to our health.

(2) it 作形式宾语代替宾语从句

第一类动词; find/ feel/ think/ consider/ make / believe/ guess/ suppose /assume等后面有宾语不足语时，需要用it 作形式宾语而将that引导的真正的宾语从句后置。

Eg： I think it necessary that we do some sporting.

第二类动词 带宾语从句时需要在从句前面加it。

这类词：hate / like/ dislike/ appreciate/ depend on/ see to /

Eg: I hate it when they talk without considering other’s feeling.

但是如果宾语从句是WH-类引导的，其后面有to be 短语作宾语补足语，不可以用it 代替。

We all consider what you said to be unbelievable. (right)

We all consider it to be unbelievable what you said .(wrong)

(3) 形容词后的宾语从句

Adj: sure / certain/ glad/ pleased/ happy / afraid / sorry 等等。

Eg; I am not sure whether you will come or not.