第一个问题：

传统语法认为引导引导地点状语从句的where是个连词。但实际上根据传统语法对连词的定义---不作分句成分，通过分析我们就可以知道其实where在引导地点状语从句时在从句中是作了成分的，where在从句中作地点状语或表语（地点副词可以作表语）。Huddleston在The Cambridge Grammar of the English Language一书中 （P1068）也指出，where和wherever都是融合型关系词，where和wherever引导的状语从句在该书中被分析为关系分句,认为这种状语从句等于一个介词短语+限制性定语从句。例如：

We must put it where no one will be able to see it.

= We must put it in a place where no one will be able to see it.

即where=in a place where, 介词+place+关系副词where融合为一个副词where，我们称之为融合型关系副词，引导副词性关系分句作状语。

You should have put the book where you found it.   (Where =in the place where)

=You should have put the book in the place where you found it.

Where they went, they were warmly welcomed. (Where =in every place where)

=In every place where they went, they were warmly welcomed.

Keep it where you see it (和1. 一样.)

=Keep it in the place where you see it.

可以看出，以上几个句子中where除了引导地点状语从句外，同时还在从句中作地点状语。

第二个问题：

A：where不仅可以在从句中作状语，还可以作表语。

There is only a vacant lot where her house used to be. (where在从句中作表语）

=There is only a vacnat lot in the place where her house used to be.

Just stay where you are. （where在从句中表语)

=Just stay in the place where you are.

B：融合型关系副词还可以引导名词性从句，此时where=the place where. 即where从句相当于一个地点名词后接限制性定语从句

C：

That is where my mother usually is at this time of a day.这个表语从句中where为融合型关系副词，作从句 的表语。

=That is the place where my mother ususally is at this time of a day.

Do you know where my bike is? 此句中的where为疑问副词，引导宾语从句，where在从句中作表语

第三个问题：地点状语从句中的引导词有 where，wherever, anywhere, everywhere.

wherever, anywhere, everywhere从句做什么成分我彻底乱成一锅粥了,请看下面例句：

You can sit wherever you like. (like后省略了不定式to sit)

= You can sit in any place where you like to sit. where在从句中作to sit的状语。

Anywhere she goes, he goes too. (anywhere在从句中作地点状语）

=To any place where she goes, he goes too.

=He goes to any place where she goes.

Everywhere I go, I find the same thing. （everywhere在从句中作地点状语）

=In every place where I go, I find the same thing.

=I find the same thing in every place where I go.

Wherever I am, I will be thinking of you. wherever引导的是让步状语从句，不是地点状语从句。wherever=no matter where）

=No matter where I am, I will be thinking of you.

第四个问题：时间状语从句例句如：

The children ran away from the orchard the moment they saw the guard.

=The children ran away from the orchard at the moment when they saw the guard.

While John was watching TV, his wife was cooking.

=During the time when John was watching TV, his wife was cooking.

When 和 where确实是类似的。区别在于where在从句中通常作必具性状语，即没有这个状语从句的意思就不完整。where还可在从句中作表语，没有表语的话从句显然结构都是不完整的。但when在从句中通常作修饰性状语，修饰性状语不影响分句结构的完整，故给人的感觉是when没有在从句中作成分。

不过，绝大多数的语法书和词典都将引导状语从句的where和when当作连词对待。除了where在从句中作表语用连词无法合理解释外，其它情况按照连词解释似乎也能讲得通。认为where，when在从句中作状语因而应该是副词是极少数人的观点。在这一点上，你最好随大流，以避免无谓的争论。