定语从句中关系词的用法

我怎么能知道关系词在句子中是不是做状语？

我分不清Which和When、where的用法

举几个例子：

This is the place where they met yesterday.

这就是他们昨天碰头的地方。

they meet in the place

the place 表示地点，做状语，所以用where

where 等于 at which (根据先行词选择at on in 等）

即：This is the place at which they meet yesterday.

This is the place which I have visited.

这是我参观过的地方。

visit the place, the place 做 visit 的宾语，所以用which

I'll never forget the day which we spent together.

spend the day, day做spend的宾语

I'll never forget the day when you went away.

you went away on the day 时间状语，用when

也可写成：I'll never forget the day on which you went away.

我们最近刚学完，自己整理的，希望对你有帮助。

定语中的关系代词有that/who/whom/which who/whom在定语从句中,主语是指人. which在定语从句中,主语是指物.(一件事) 而that是通指的. 定语从句中关系词省略的6种情形关系词有时可以省略，但这只限于限制性定语从句中，在非限制性定语从句中，关系词则不可省略。 一、关系代词作宾语时的省略当关系代词who, whom, which和that在定语从句中用作动词宾语或介词位于句末时的介词宾语时，可以省略。如：在定语从句中用作动词宾语或介词位于句末时的介词宾语时，可以省略。如：Is there anything (which) you wanted? 想要什么东西吗? Who is the man (that / who / whom) you were talking to? 刚才和你讲话的人是谁? 二、关系代词作表语时的省略当关系代词that在定语从句中用作表语时，可以省略。如：China is not the country (that) it was. 中国已不是过去的中国了。(that作表语) 三、关系代词作宾补时的省略当关系代词that在定语从句中用作宾语补足时，可以省略。如：I’m not the madman (that) you thought me. 我并不是你所认为的那个疯子。(that作宾语补语) 四、关系副词when的省略用作时间状语的关系副词when通常不能省略，但有一种特殊情况，即用于day, year, time等少数几个词后时可以省略(也可换成that)也可换成。如：That was the year (that) I first went abroad. 就是那一年我第一次出国了。I’ll never forget the day (that) we met. 我永远也忘不了我们见面的那一天。 五、关系副词where的省略用作地点状语的关系副词where通常不能省略，但有一种特殊情况，即用于place, somewhere, anywhere, everywhere, nowhere少数几个词后时可以省略(也可换成that)。如：This is the place (where) they met yesterday. 这就是他们昨天碰头的地方。Have you somewhere (that) I can lie down for an hour? 你有没有一个什么地方可以让我躺一个小时？ 六、关系副词why的省略关系副词why通常只用于the reason后引导定语从句，且通常可换成that或for which，均可省略。如：That’s the reason (why, for which, that) he came. 这就是他来的原因。 Give me one reason (why) we should help you. 给我举出一个我们应当帮助你的理由。 absent, nothing couldn’t be done. 由于他缺席，什么事也干不