什么叫复句？语法里讲的。

复句也叫复合句。

英语按句子的结构可分三种：

1）简单句：只有一个主语（或并列主语）和一个谓语（或并列谓语）。

He often reads English in the morning.

Tom and Mike are American boys.

2) 并列句：由并列连词（and, but, or等）或分号（；）把两个或两个以上的简单句连在一起构成。

You help him and he helps you.

The future is bright; the road is tortuous. 前途是光明的，道路是曲折的。

3）复合句：含有一个或一个以上从句的句子。复合句包含：名词性从句（主语从句、宾语从句、表语从句和同位语从句）、定语从句和状语从句等。

The foreign visitors took a lot of pictures when they were at the Great Wall.

Who will go to the conference is not important.