初中英语从句主要包括名词性从句、定语从句和状语从句。名词性从句可以作为主语、宾语、表语或同位语，常见的引导词有that, whether, who等。定语从句修饰名词或代词，通常由that, who等引导。状语从句可以修饰整个句子，作为句子的状语，常见的引导词有if, when等。
名词性从句
名词性从句可以作为主语、宾语、表语或者同位语。常见的名词性从句有三种类型：主语从句、宾语从句和表语从句。
主语从句：是句子的主语，常见的引导词有that, whether, who, whom, what, which等。
例如：What I want to say is that you need to work harder.
宾语从句：作为句子的宾语，通常由that, if, whether, who, whom, what, which等引导。
例如：I don't know whether he will come or not.
表语从句：作为句子的表语，通常由that, whether, who, whom, what, which等引导。
例如：The fact is that he is not coming to the party.
定语从句
定语从句修饰名词或代词，通常由that, who, whom, whose, which等引导。
例如：The girl who is singing is my friend.
状语从句
状语从句可以修饰整个句子，作为句子的状语。常见的引导词有if, when, because, although, unless等。
例如：Although it is raining, we still need to go to school.
