1、在复合句中，由一个句子充当宾语，这个句子叫做宾语从句。宾语从句主要有三种类型，分别是that引导的宾语从句、if或whether引导的宾从、连接代词和连接副词引导的宾语从句。 常见的宾语从句引导词：that、if、whether、what、who、where、why和how。

Eg. I am sad that you refused me. 我很难过你拒绝了我。

2、定语从句在中考和高考中出现的频率都非常高。在复合句中，修饰名词或代词的从句叫定语从句。被修饰的名词或代词叫先行词。定语从句一般放在先行词的后面。常见的关系代词包括that,which,who（宾格whom，所有格whose），as 等，关系副词包括where,when,why等。

Eg. Lily likes music that is quiet and gentle. 玛丽喜欢轻柔的音乐。

3、状语从句就是由一个句子在复合句中充当状语。所以状语从句又可以分为时间状语从句、地点状语从句、原因状语从句、目的状语从句、结果状语从句等等。每种状语从句都有特定的引导词：

地点状语从句：where,wherever.

时间状语从句：when, while, as, before, until, till, since.

原因状语从句：because, since,as, now that, not that…， but that…， seeing that,considering that, in that.

目的状语从句：so, so that, in order that, that, to the end that, in case,for fear that,lest.

结果状语从句：so…that, such that, so that, with the result that.

条件状语从句：if,unless,if only,only if,in。 case,suppose/supposing.（that），provided/providing（that），on condition that,so/as long as

方式状语从句：as, as if, as though.

让步状语从句：though, although, as, even if, even though, whether, no matter whether…or, no matter with.