句子的結(jié)構(gòu)

那個全家人依靠的頂梁柱昨天死于一場交通事故。
關(guān)系代詞that和關(guān)系副詞when，where等都不能作介詞的賓語。
the house in which they are living was built 50 years ago.
他們現(xiàn)在正居住的房子是50年以前建的。(不能說：the house in that they are living w as built 50 years ago.)
如果不用關(guān)系詞，介詞要放在從句句尾。
the house they are living in was built 50 years ago.
他們現(xiàn)在居住的房子建于50年以前。
(3)限制性定語從句和非限制性定語從句
從句與主句關(guān)系密切，沒有從句主句不能成立，這樣的句子為限制性定語從句；
從句與主句關(guān)系松散，對主句只起補充和說明的作用，沒有從句主句仍然成立，這樣的句 子叫非限制性定語從句。該從句要用逗號與主句分開。
her boyfriend who is working abroad will return home next week.
(限制性從句)
她的在國外工作的男友下周要回國。
her boyfriend, who works abroad, will return home next week.
(非限制性從句)
她的男友下周回國，他在國外工作。
(補充說明她的男友在國外工作這一情況)
those boys and girls who wanted to go hiking were very joyful.
想去野游的同學(xué)們都非常高興。
those boys and girls, who wanted to go hiking, were very joyful.
那些同學(xué)很高興，他們要去野游。
4.表語從句
以從句的形式作表語，叫表語從句。
表語從句常以that，what，why，where和how等關(guān)系代詞或關(guān)系副詞引導(dǎo)。
(1)that，if，whether可以引導(dǎo)表語從句，但有時也用because，as，as if，as though等引導(dǎo)表語從句。
the reason is that he kept working hard at his studies all the time.
原因是他一直刻苦學(xué)習。
my idea is that you should eat less and take more exercise.
我的看法是你應(yīng)少吃多活動。
it looks as if it will clear up.
看起來天要晴了。
why did she leave?
it is because she was annoyed at your word.
她為什么走了?
因為她非常煩你說的話。
(2)用what，who，which等連接代詞引導(dǎo)：
that's what i want to say.
那就是我所要說的話。
the question is who will be sent there.
問題是要派誰去那里。
his trouble is which colour he should choose for her.
他發(fā)愁該為她選擇哪種顏色。
(3)用when，how，where，why等連接副詞引導(dǎo)：
the problem is how we can find out the reason.
問題是我們怎樣才能找出原因。
that is why he came to see you last week.
那就是為什么他上星期來看你的原因。
5.狀語從句
按照它們在句中的作用，狀語從句可分為九種：時間，地點，原因，條件，方式，讓步，比 較，結(jié)果，目的狀語從句。(詳細情況參考第十二章連詞)
(1)時間狀詞從句
引導(dǎo)時間狀語從句的連詞有：when，while，before，after，till(until)，as，since，a s soon as，once(一旦)，now that(既然)，whenever，during the time(在……期間)等。
tell him to come to me when you see him.
你看見他時，讓他到我這兒來一趟。
strike while iron is hot.
趁熱打鐵。
she won't go back home until the rain stops.
她要等到雨停了才回家。
注意：主句是將來時，從句要用一般現(xiàn)在時。