4.關系代詞的格應與它在從句中充當的成分一致。特別要注意插入語，

　　如：Peter is the one who everybody believes will fail to bring off the contract. Peter 是那個人人都認為不能完成合同的人。(everybody believes 是插入語)

　　At the election I voted for the man whom I believed to be the most suitable.

　　在選舉的時候我投了我認為最合適的那個人的票。

　　5.關系代詞作從句的主語時，從句的動詞必須和先行詞的人稱和數一致：

　　例：These are the operating instructions that/which are written in English 。

　　這就是用英文寫成的使用說明。

　　Are you staying at the white house which/that is newly completed and which /that has 15 bedrooms, 3 kitchens and 4 toilets?

　　你是住在那幢剛剛竣工、有15個臥室、3個病房和4個衛生間的白色房子里嗎?

　　So far as I know, there are many VIPs who are going to attend the reception.

　　就我所知有很多達官貴人將出席這個招待會。

　　6.非限定性定語從句不用that，只用who(whose, whom)和which代表人和物;

　　例：Her brothers, both of whom work in America, ring her up every week。

　　她的兄弟們??兩個人都在美國工作??每個星期都給她打電話。

　　The buses, most of which were already full, were surrounded by an angry crowd，

　　那些公共汽車??大多已經坐滿了人??被一群憤怒的人圍著。

　　That tower block, which cost five million dollars to build, has been empty for five years.

　　那個塔樓空著已經5年了。建它花了500萬美元。

　　Cricket, which I know very little about, is a very popular sport in England。

　　板球是英格蘭非常流行的體育活動，我對它知之甚少。

　　The accounts of the company ,which I’ve been paying great attention to, are in balance.

　　公司的賬目是保持平衡的。我一直非常注意這些賬目。

　　7.關系副詞(=介詞+關系代詞)：

　　例：I shall never forget the day when (=on which) we first met.

　　我永遠也不會忘記我們第一次見面的那一天。

　　The rain came at a time when (=at which) it was not needed.

　　雨下得不是時候。

　　This is the computer where (=by/on which) he has stolen top-secret documents.

　　這就是他用來盜竊絕密文件的計算機。

　　Here is the place where (=at which) the murder took place.

　　這就是謀殺發生的地方。

　　He didn’t give any reason why (=for which) I had been fired.

　　他沒給任何解雇我的理由

　　This is the house in which (=where) my parents used to live.

　　這就是我父母以前住過的房子。