2016英语六级定语从句精讲
想要学好英语六级怎么能不知道定语从句的用法呢?下面就让小编为大家详解一下吧。
1.指人的关系代词：who, whom, whose, that 的用法：
(1)作主语(who, that )
Those who are going to play in the match are to meet at the gate at 1:30 after lunch. 那些参加比赛的人午饭后1：30在大门口集合。
在本句中，先行词是those;关系代词who引导定语从句，同时代替先行词在从句中担任动词are going to play 的主语。
The man who/that is talking with Mr. Wang is a famous doctor. 正在和王先生说话的那个人是一个有名的医生。
在本句中，先行词是the man;关系代词who/that引导定语从句，同时代替先行词在从句中担任动词is talking的主语。
这个复合句可以还原成两个句子：The man is a famous doctor. He is talking with Mr. Wang.
(2)作宾语包括作介词宾语(whom, that )。此种情况下的关系代词可以省略;
This is just the man(whom/that) I want for the job.这正是我要的做这份工作的人。
在本句中，先行词是the man;关系代词whom/that 引导定语从句，同时代替先行词在从句中担任动词want 的宾语。
(3)当关系代词紧跟介词作介词宾语时，不能用that，也不能省略，
如：The book from which I got a lot of useful information was written by a famous scientist.
我从中得到许多有用信息的那本书是一位著名科学家写的。
但是当介词放在从句末尾时，作为介词宾语的关系代词可以用that 并且可以省略。
如上头两句可改为：
The book (that /which) I got a lot of information from was written by a famous scientist.
2.指物的关系代词which和that的用法：
(1)作主语
This is the instruction manual which/that tells you how to operate the computer. 这是那本教你如何操作计算机的说明手册。
(2)作宾语包括作介词宾馆。此种情况下的关系代词可以省略：
The chair (which /that) you broke yesterday is now being repaired. 你昨天弄坏的那把椅子现在正在修理。
The accounts of the company, (which/that) I’ve been paying great attention to, are in balance.
我一直非常注意的公司账目，是保持平衡的。
3.whose 和of which 指代人或事物，作定语。of which 可用whose 代替; The car whose lights (of which the lights/the lights of which) were all broken was my father’s.
那辆所有的灯都破了的汽车是我父亲的。
That is the book whose cover (of which the cover/the cover of which ) was broken. 这就是那本封皮破了的书。
4.关系代词的格应与它在从句中充当的`成分一致。特别要注意插入语，
如：Peter is the one who everybody believes will fail to bring off the contract. Peter 是那个人人都认为不能完成合同的人。(everybody believes 是插入语) At the election I voted for the man whom I believed to be the most suitable. 在选举的时候我投了我认为最合适的那个人的票。
5.关系代词作从句的主语时，从句的动词必须和先行词的人称和数一致： 例：These are the operating instructions that/which are written in English 。 这就是用英文写成的使用说明。
6.非限定性定语从句不用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。 她的兄弟们??两个人都在美国工作??每个星期都给她打电话。
7.关系副词(=介词+关系代词)： 关系副词 先行词 在从句中的作用 说明 when(=at / on / in /during which),非正式文体中，有时用that代替关系副词
where(=in / at which) 地点名词 地点状语
why=(for which) 只有reason 原因状语
例：I shall never forget the day when (=on which) we first met. 我永远也不会忘记我们第一次见面的那一天。
延伸阅读：
1、might 不是 may 的过去式而是表示一种很小的可能性。Might 如果用完成式则表示过去发生的很小的可能性。如：You might have told me that.
2、作为情态动词 need 和 dare 除在 whether 和 if 引出的从句中以外，一般不能用于肯定句，只能用于否定句和疑问句，并且不采用助动词 do，但是作为实义动词则需要 do,试比较
He doesn’t need/dare to do it.
He needn’t/dare not to do it.
3、used to 表示过去习惯的动作或者状态，即现在已经不存在了，be used to doing 则表示习惯于某种状态。
4、might 和 as well 连用表示建议，口气比同样表示建议的 had better 要婉转一些，两种用法后面都要跟动词原型。
5、ought to，should be，must be/must have been，will be 用来表示论断、逻辑推理等。如：He ought to be here by now.再如：
“Mary isn’t here now.”
“left by the back door?”
A.Must she have
B.Might she have
C.Had she
D.Should she have
根据以上所讲的第一点，B 选项表示过去发生的很小的可能性，前半句说玛丽不在这里了，后半句理应对于她去了哪里作一个推测，由于不确定，用的是问号，所以正确答案是 B。