定语从句怎么讲精彩

　　概念

　　被修饰的词叫先行词。定语从句不同于单词作定语的情况，它需要放在被修饰的词(即先行词)之后。定语从句一般由关系代词来引导。关系代词必须放在定语从句之首。定语从句(Attributive Clauses)在句中做定语，修饰一个名词或代词，被修饰的名词,词组或代词即先行词。定语从句通常出现在先行词之后，由关系词(关系代词或关系副词)引出。

　　关系代词引导的定语从句

　　关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。

　　1)who, whom, that

　　这些词代替的先行词是人的名词或代词，在从句中所起作用如下：

　　Is he the man who/that wants to see you?

　　他就是想见你的人吗?(who/that在从句中作主语)

　　He is the man whom/ that I saw yesterday.

　　他就是我昨天见的那个人。(whom/that在从句中作宾语)

　　1）who， whom， that

　　这些词代替的先行词是人的名词或代词，在从句中作主语和宾语。例如：

　　Is he the man who/that wants to see you？他就是你想见的人吗？（who/that在从句中作主语）

　　He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。（whom/that在从句中作宾语）

　　2） whose 用来指人或物，（只用作定语，若指物，它还可以同of which互换）。例如：

　　They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。

　　Please pass me the book whose （of which） cover is green. 请递给我那本绿皮的书。

　　3）which， that所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等。例如：

　　A prosperity which / that had never been seen before appears in the countryside.

　　农村出现了前所未有的繁荣。（which / that在句中作宾语）

　　The package （which / that）you are carrying is about to come unwrapped. 你拿的包快散了。（which / that在句中作宾语）

　　练习题：

　　【陷阱】容易误选A。有的同学一看到空格前的情态动词 could 就断定此处应填动词原形 enter。

　　【分析】其实正确答案应是B。此句为省略句，即在 could 后省略了动词 do，若把句子补完整应为Everyone in our class was working hard and doing what we could do to enter a good college。即句中的不定式短语(to enter a good college)是用作目的状语的，而不是与情态动词(could)一起构成谓语。请再看类似例句：

　　(1) They did what they could to comfort her. 他们尽量安慰她。

　　(2) They did everything they could to save her life. 他们尽一切力量拯救她的性命。

　　(3) He studies as hard as he could to catch up with his classmates. 他拼命学习以便赶上他的同学。

　　值得指出的是，这也并不是说今后只要遇到类似结构的题就一定选带to不定式。请看以下试题：

　　(4) He ran as fast as he could _____ to catch the early bus.

　　A. to hope B. hope

　　C. hoping D. hoped

　　此题的答案是 C不是A，其中的.现在分词短语 hoping to catch the early bus 用作伴随状语。

　　(5) He spent every minute he could _____ spoken English.

　　A. practise B. to practise

　　C. practising D. practised

　　此题答案选 C，这与前面动词 spent 的搭配有关，即 spend … (in) doing sth。若将此句补充完整，即为 He spent every minute he could spend in practising spoken English.

　　(6) Before going abroad he devoted all he could ____D____ his oral English.

　　A. improve B. to improve

　　C. improving D. to improving

　　此题答案选D，注意两点：一是 devote … to … 是固定搭配，意为“把……贡献给……”;二是其中的 to 是介词，不是不定式符号，后接动词时要用动名词。

　　2. He knows nothing about it, so he can’t help _______ any of your work.

　　A. doing B. to do

　　C. being doing D. to be done

　　【陷阱】容易误选B，根据 can’t help doing sth 这一结构推出。

　　【分析】其实答案应选A。比较以下结构：

　　can’t help to do sth = 不能帮助做某事

　　can’t help doing sth = 禁不住做某事，情不自禁地做某事

　　又如下面一题，答案也是 B：

　　She can’t help ____ the house because she’s busy making a cake.

　　A cleaning B. to clean

　　C. cleaned D. being cleaned

　　再请看以下试题：

　　While shopping, people sometimes can’t help _____ into buying something they don’t really need.

　　A. to persuade B. persuading

　　C. being persuaded D. be persuaded

　　此题应选C，句中的 can’t help 意为“禁不住”(注意根据句意用被动形式)。

　　3. All her time _______ experiments, she has no time for films.

　　A. devoted to do B. devoted to doing

　　C. devoting to doing D. is devoted to doing

　　【陷阱】几个干扰项均有可能误选。

　　【分析】此题最佳答案为B。现分析如下：

　　(1) devote 意为“致力于，献身于”，主要用 devote…to…或be devoted to，其中的to 是介词，不是不定式符号，故后接动词时要用动名词，不用不定式。

　　(2) 选A错误：若将 do 改为 doing 则可以。

　　(3) 选B正确：all her time devoted to doing experiments为独立主格结构，用作状语。

　　(4) 选C错误：因为all her time 与 devote 为被动关系，故应将devoting改为devoted。

　　(5) 选D错误：若单独看 All her time is devoted to doing experiments，此句并没有错，但问题是逗号前后两个简单句没有必要的连接方式，所以从整体上看仍不对，假若在后一句的句首加上and或so，则可选D，或将D将中的is 改为 being也可选它。

　　英语语法经典例题800例：虚拟语气（例题）

　　【导语】英语语法让很多学生都头疼，因为复杂难懂的句式和词组有时难以记忆。为大家整理了英语语法大全，希望对同学们的英语语法学习有所帮助。更多内容尽在。

　　1. I forget where I read the article, or I _____ it to you now.

　　A. will show B. would show

　　C. am going to show D. am showing

　　【陷阱】几个干扰项均有可能误选。

　　【分析】正确答案选B。根据上文的语境可知句中的 or 隐含有一个虚拟的条件，即 or=if I didn’t forget where I read the article(要是我没忘记我在哪儿读过这篇文章的话——但事实上忘了)。

　　2. “It looks as if he were drunk.” “So it does. _____.”

　　A. He’d better give up drinking

　　B. He shouldn’t have drunk so much

　　C. Health is more important than drink

　　D. I wonder why he is always doing so

　　【陷阱】几个干扰项均有可能误选，主要是受句中 drunk 一词的影响。

　　【分析】最佳答案为D。关键信息是It looks as if he were drunk 中的虚拟语气，句子既然用了虚拟语气，也就是说，“他喝醉了”不是事实，只是他的言行好像是醉了，所以此题的最佳答案是D。

　　3. “Mary looks hot and dry” “So _____ you if you had so high a fever.”

　　A. do B. are

　　C. will D. would

　　【陷阱】容易误选A或C。选A者，认为前后两句的动词性质应一致;选C者，认为其后带有if 条件状语从句，从语气上看，主句应用将来时态。

　　【分析】此题最佳答案为D。分析如下：

　　(1) “so + 助动词 + 主语”是一个很有用的结构，它表示“……也一样”时。如：

　　He likes to watch TV, and so do I. 他喜欢看电视，我也一样。

　　When animals and plants disappear, so will man. 当动植物消失的时候，人类也会随之消失。

　　(2) 由于空格后的 if 条件状语从句的谓语用的是虚拟语气(这是很重要的信息)，所以主句要用 would 而不用 will，即答案应选D。

　　英语语法经典例题800例：强调句（例题）

　　1. ____ that caused him to serve dinner an hour later than usual.

　　A. It was we being late B. It was our being late

　　C. It was we were too late D. It was because we were late

　　【陷阱】此题容易误选D，认为强调的是原因状语从句 because we were late。

　　【分析】但实际上，此题的答案为B，强调的是句子主语 our being late，此题若还原成非强调句，即为：

　　Our being late caused him to serve dinner an hour later than usual.

　　注意，强调句的一个显著特点是，若去掉强调结构 it is [was]… that…，句子仍然成立;换句话说，该结构中的 that 不能充当句子成分。

　　2. “How was ______ they discovered the entrance to the underground palace?” “Totally by chance.”

　　A. it that B. he that

　　C. it when D. he which

　　【陷阱】几个干扰项均可能误选。

　　【分析】答案选A，为强调句的特殊疑问句形式，其相应的陈述句形式为：

　　It was totally by chance that they discovered the entrance to the underground palace.

　　比较以下各题，它们也属强调句的特殊疑问句形式：

　　(1) Who was it _____ saved the drowning girl?

　　A. since B. as C. that D. he

　　答案选C，被强调成分为 who，该句实为类似 It was Tom that saved the drowning girl. 这类强调句的特殊疑问句形式(即对其中的Tom 提问而得)。

　　(2) What is it _____ his daughter needs most?

　　A. what B. which C. that D. if

　　答案选C，被强调成分为 what，该句实为类似 It is a bike that his daughter needs most. 这类强调句的特殊疑问句形式(即对其中的a bike 提问而得)。

　　3. _____ was very ______ that little Jim wrote the letter.

　　A. It, careful B. It, carefully

　　C. He, careful D. He, carefully

　　【陷阱】几个干扰项均有可能误选，但最有可能误选的可能是A，认为这是一个普通的系表结构，即认为第二空要填形容词作表语。

　　【分析】其实，此题是一个强调句，其非强调形式为 Little Jim wrote the letter very carefully. 若用 it is … that… 的强调句式强调其中的状语 very carefully 即为上面一题的题干，所以答案应选B。请看下面几例，也属强调结构：

　　(1) It was when she was about to go to bed ______ the telephone rang.

　　A. since B. as C. that D. then

　　答案选C，被强调成分为 when she was about to go to bed 这一时间状语从句。

　　(2) It may have been at Christmas _____ John gave Mary a handbag.

　　A. before B. who C. that D. when

　　答案选C，被强调成分为 at Christmas，其中的动词 be 采用了 may have been 这一较为复杂的形式。

　　4. “Where did you find the professor who made the speech yesterday?” “It was in the hall ______ the students

　　often have a meeting.”

　　A. where B. which

　　C. that D. when

　　【陷阱】很可能误选C，认为这是一个强调句，强调地点状语 in the hall。

　　【分析】假若选C，即有 It was in the hall that the students often have a meeting，该句的意思是“学生们通常是在