初中英语从句类型与用法总结如下：

一、从句的基本分类

名词性从句

- 主语从句：

在句中作主语，例如：

*What he said was true.*

- 宾语从句：在句中作宾语，例如：

*I believe that he will succeed.*

- 表语从句：在句中作表语，例如：

*The reason why he is late is that he had an accident.*

- 同位语从句：对名词进行解释说明，例如：

*This is the computer on which he spent all his savings.*

定语从句

修饰名词或代词，由关系代词（如that, which, who）或关系副词（如where, when）引导，例如：

*She is the student who can speak English well.*

*This is the book that I borrowed yesterday.*

状语从句

表示时间、原因、条件、结果等关系，例如：

- 时间状语从句：

*As soon as the meeting starts, we'll leave.*

*When she arrived, the movie had already started.*

- 原因状语从句：

*Because of the rain, the match was canceled.*

- 条件状语从句：

*If it rains tomorrow, we will cancel the picnic.*

- 结果状语从句：

*He lost so many bikes that he decided never to buy a new one.*

- 让步状语从句：

*Although it was raining, we still went for a walk.*

二、重点类型解析

定语从句

- 限定性定语从句：

用that, which, who等引导，例如：

*This is the house where we grew up.*

- 非限定性定语从句：用which, that等引导，可置于句首、句中或句尾，例如：

*She is the friend of my father, who lives in London.*

状语从句

- 时间状语从句：

*As soon as the signal is green, we can cross the road.*

*Since last year, we have been saving money.*

- 条件状语从句：

*If you finish your homework, you can watch TV.*

*Unless it rains, we'll go hiking.*

- 让步状语从句：

*Even if I fail the exam, I won't give up.*

名词性从句

- 主语从句：

*Whether she will call you depends on her schedule.*

- 宾语从句：

*I wonder if we can meet tomorrow.*

- 表语从句：

*The problem is how to solve it.*

- 同位语从句：

*This is the theory that explains the phenomenon.*

三、注意事项

时态搭配：条件状语从句中，若主句为一般将来时，从句用一般现在时（如：If you call, I'll help）；时间状语从句中，主句为过去时，从句用过去完成时（如：She had finished her homework when I arrived）。

省略规则：宾语从句中，若从句主语与主句主语一致且谓语为be动词，可省略主语（如：I believe that he is right）。

通过掌握以上分类与用法，学生可系统理解英语从句的构造与功能。