主句过去式,从句过去式。
主句一般现在时,从句任意时态。
主句将来时，从句一般现在时。
定语从句
一、 定语从句与引导词
定语从句是在复合句中修饰某一名词或代词的从句。被修饰的名词或代词叫做选行词，
而引导定语从句的词叫引导词，有关系代词和关系副词两类。
懂得什么样的先行词后用什么样的引导词是学好定语从句的关键。
1． 关系代词有：that,which,who,whom,whose,在定语从句中作主语、宾语中表语，whose
作定语。代人的有：who,whom,whose,that；代物的有：that,which,whose.例如：
The man who helped you is Mr White.(who代人，在定语从句中作主语)
That is the person(whom/who/that) you want to see.(whom,who,that代人，在定
语从句中作宾语，可省略)
I´m not the fool(that) you thought me to be.(that代人，在定从中作表语)
A dictionary is a useful book which(＝that) tells us the meaning of words(which
或that代物，在定从中作主语)
2． 关系副词有：when(指时间)，where(指地点),why(指原因)，在定语从句中作状语。
例如：Would you suggest a time(when) we can have a talk?(when可省略)
The house where they live is not very large./This is the reason why he did not came to the meeting.
注意：不是表时间的先行词都用when引导定从，不是表地点的先行词都用where引导定从。例如：We´ll visit the factory which(＝that) makes radios.
(which或that在定从中作主语，where不可用主语，故不可用)
They still remember the happy days(which/that) they spent in Beidaihe.
(which或that在定从中作spent的宾语，when不可作宾语，故不可用)
二、限制性定语从句与非限制性定语从句
限制性定语从句和主句之间不用逗号分开，修饰主句中的某一个名词或名词词组或代
词；非限制性定语从句常用逗号和主句隔开，可以修饰主句中的某一个词，也可修饰整个句子。非限制性定语从句不能用that引导，引导非限制性定语从句的关系词不能省略。非限制性定语从句例：Li Ping´s father, who works in a factory, is an engineer./He tore up my photo, which made me very angry.(which指代主句内容，因前后两句是因果关系，此时which不可换为as。)
He is good at physics, as is known to us all.＝As is known to us all, he is good at physics.(as指代主句内容，在as is known/believed, as we all know/believe这类结构中as不可换为which)
三、 只用that引导和不用that引导的场合
1． 只用that引导和不用that引导的场合
1） 当先行词既包括人又包括物时：He talked about the men and the books that attracted
him.
2） 指物的先行词被any, every, only, very, all, no等修饰时：These are the very points that interest me./That´s the only watch that I like most.
3） 指物的先行词被序数词或形容词最高级修饰时：The first step that we are to take is very difficult./This is the second card that he gave me.
4） 先行词是指物的不定代词all,little,few,much,及everything,anything,nothing等时：There is still much that can be done about it./Have you got everything that you need?
5） 先行词是who时：Who that have seen him does not like him?
2． 不用that的场合如下：
1）非限制性定语从句中 Last night ,I saw a very good film,which was about the Long
March .
2）介词放在关系代词之前时 This is the man from whom I learnt the news
3）句中出现了that，或先行词是that时 I have found that which I was looking for.
四、“介词＋关系代词”用法
1． 介词的确定应依据定语从句中短语的习惯性搭配，例如：Who is the girl with whom you just shook hands?(shake hands with…是习惯性搭配)
2． 介词常受先行词的制约（即介词和先行词的搭配），例如：He built a telescope through which he could study the skies.(through which 即through the telescope)
3． 当关系代词作“动词＋介词”固定短语的宾语时，此时因定短语中的介词不能拆开移到关系代词前。例如：This is the watch which you´re looking for./He is a kind of man whom you can safely depend on.
五、几个名词后的引导词
1. situation后常用where,in which引导定语从句：Can you imagine a situation where/in
which you can use the word?
2. way(方式，方法)后常用in which或that或how引导定语从句，也可省略：Do you know the way(in which/that/how) he worked out the problem?
3. “the same＋名词”，“such＋名词”，“as＋名词”后通常用as引导定语从句。
例如：I have the same dictionary as you(have)./Such a book as you bought is not worth buying.
宾语从句（一） 宾语从句在复合句中作主句的宾语。宾语从句常由that引导，在口语中常省略。 当主句中谓语动词是现在或将来时态时，从句中谓语动词不受主句中谓语动词时态的 影响，按需要可以使用任何时态。如： She says (that) she works from Monday to Friday. 她说她从周一至周五上班。（从句是一般现在时） She says (that) she will leave a message on his desk. 她说她要在他桌子上留个便条。（从句是一般将来时） She says (that) she has never been to Mount Emei. 她说她从来没有去过峨眉山。（从句是现在完成时） 当主句谓语是过去时态，从句中的时态一般用表示过去的某种时态。如： He said there were no classes yesterday afternoon. 他说昨天下午没有课。（从句是一般过去时） He said (that) he was going to take care of the baby. 他说他会去照看这个婴儿。（从句是过去将来时） He said (that) they were having a meeting at that time. 他说他们那时正在开会。（从句是过去进行时） *当主句谓语是过去时态，而宾语从句叙述某一客观真理（事实）时， 宾语从句的时态则用一般现在时。如： The teacher told us(that) nothing is difficult if you put your heart into it. 老师告诉我们世上无难事只怕有心人。 She said (that) her father is twenty-eight years older than her. 她说她父亲比她大二十八岁。 He said that light travels much faster than sound. 他说光传播比声音传播快得多。 宾语从句（二） 由连接代词或连接副词引导的宾语从句。 引出名词性从句的连词whether和if，在引出宾语从句时，用法和意义相同。但是只能引出宾语从句和不在句首的主语从句，而whether除了引出宾语从句外，还可引出主语从句、表语从句和同位语从句。例如： We don't know whether (if) it is right. 我们不知道它是否正确。 The question is whether she should do that. 问题在于她是否应该做那件事。 Whether it is true remains a question. 是真是假还是个问题。 试比较： 当if从句处在主句之后作“是否”讲时，引出的是宾语从句。例如： I don't know if it is true. 我不知道这事是否真实。 当if从句在主句之前作“如果”讲，则引出状语从句。例如： I shall go there if I have time. 如果我有时间，我将到那儿去。
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