我们已经看完了三种复合句，分别是名词性从句、定语从句和状语从句。看下来这三种从句都是连接词加一个句子，其连接词还可能是一样的，那我们怎么区分它们呢。现在让我们重新梳理一下学过的知识，找出他们的区别。

名词性从句

结构：连接词 + 陈述句

I wonder when we will set out.
You never told me what you had done to my computer.
The happiest thing is that he will come.
It is acknowledged that the internet has changed the world.
Their findings support the view that fun may indeed have a beneficial effect.

• 名词性从句在主句中是做成分的，可以做宾语(动宾或介宾)、表语、主语和同位语。
• 连接词在从句中也是做成分的。

定语从句

结构：先行词n. + 关系词 + 陈述句

This is the job which I have dreamed of for years.
Australia is one of the few countries where people drive on the left.
I met your friend who is staying in Paris.

• 定语从句不做主句的成分，只是对先行词进行修饰限定。
• 连接词在从句中也是做成分的。

状语从句

结构：从属连词 + 完整的陈述句

I will let you know when he comes back.

• 状语从句不做主句的成分，只是围绕主句表达描述性的信息。
• 从属连词不在从句中充当成分，只表达含义