例如:This is the house甲I was barn and brought up in the house.在這兩個句子中，in the house是句子里的地點狀語，定語從句修飾的就是the house。把后面這一句變成定語從句。在將要被變成定語從句的句子中，in the house是地點狀語，所以用where來代替它。然后再把where放到本句的最前面，其它的詞和語序來代替它。然后再把where放到本句的最前面，其它的詞和語序一律不變。這時，就成了"where}was barn and brought up"。再把這個定語從句整個放在被修飾的詞后面，就成了"This is the house where I was barn and brought up.”，

　　定語從句就完成了，主句是陳述句，所以句末用句號。Where代替的是原句中的狀語，原句變成了從句，它就作從句的狀語。

　　(4) The hotel is an artistic building. We' 11 stay in it.

　　……The hotel where we' 11 stay is an artistic building.

　　……The hotel (which/that) we' 11 stay in is an artistic building.

　　……The hotel in which we' 11 stay is an artistic building.

　　(5) Perhaps they' ve heard of the place. We went there for our holidays last time.

　　……Perhaps they' re heard of the place where we went for our holidays last time.

　　定語從句

　　請讀者照上面的例子，把下面變定語從句的步驟說出來(括號里的可以省略)：

　　(6)They’re redecorating the room. A conference will be held in the room.

　　→They’re redecorating the room where a conference will be held.

　　→They’re redecorating the room (which /that) a conference will be held in.

　　→They’re redecorating the room in which a conference will be held.

　　那么，“介詞+關系代詞”是怎么回事呢?原來上面這個例句，還有一種做法：This is the house. I was born and brought up in the house.在這兩個句子中，the house是相同的，定語從句修飾的就是the house 。把后面這一句變成定語從句。在將要被變成定語從句的句子中，the house表示物而且是介詞in的賓語，所以用關系代詞which或that來代替。然后把which或that放到本句的最前面，其它的詞和語序一律不變。這時，后面這一句就成了 “which/that I was born and brought up in”。再把這個定語從句整個放在被修飾的詞后面，就成了“This is the house which/that I was born and brought up in”。定語從句就完成了，主句是陳述句，所以句末用句號。

　　which/that代替的是原句中的賓語，原句變成了從句，它們就作從句的賓語。關系代詞在從句中作賓語時可以省略，因此上句又可變成“This is the house I was born and brought up in.”

　　但是，in可以提到關系代詞的前面，不過這時不能用that，而且不能省略。所以上句又可變為“This is the house in which I was born and brought up.”這就是“介詞+關系代詞”的來歷。

　　定語從句又分為限定性定語從句和非限定性定語從句。限定性定語從句把它的先行詞限定在特定的意義之內，對先行詞起限定的作用、是先行詞必不可少的修飾語，沒有它，整個句子的意思就會受到影響、就不完整。非限定性定語從句不對先行詞起限定的作用，不是先行詞必不可少的修飾語，只對先行詞起補充說明的作用，沒有它，整個句子的意思不會受到影響、仍然完整。非限定性定語從句相當于一個分句，翻譯時也是把它當作分句處理的。非限定性定語從句和它的先行詞之間要用逗號隔開;而限定性定語從句和它的先行詞之間不能用逗號隔開。非限定性定語從句中除了不用that以外，其它關系詞都可使用，使用方法與限定性定語從句一樣。

　　例如：The supermarket which was opened two months ago is now closed down.

　　兩個月前開的那家超市現在已經倒閉了。(限定)

　　The supermarket, which was opened two months ago, is now closed down.

　　那家超市現在已經倒閉了，那家超市兩個月前開的。(非限定)

　　The book(which) you’re reading is mine .

　　你正在讀的那本書是我的。(限定)

　　The book, which you’re reading, is mine.

　　那本書是我的，你正在讀那本書。(非限定)

　　如果以上例子的差別不十分明顯，再看下面的例句：

　　I’ve been to London , which is a beautiful city。