（一）情态动词
一．情态动词的现在完成式的用法
情态动词现在完成式主要有两个功能：表示已经发生的情况和表示虚拟语气。在这两个方面must/mustn’t,;can/cann’t;need/needn’t;may/mayn’t;might/mightn’t;should/shouldn’t;ought等情态动词＋完成式表示的意思是有一定区别的
1．表示已经发生的情况。
1）must have+过去分词，表示对已发生情况的肯定推测，译为“（昨天）一定……”。如：
My pain apparent the moment I walked into the room, for the first man I met asked sympathetically:” Are you feeling all right?”
[A] must be [B] had been [C] must have been [D] had to be
（答案为C）
2）can’t / couldn’t have+过去分词，表示对已发生情况的否定推测，译为“（昨天）一定没……”。如：
Mary my letter; otherwise she would have replied before now.
[A] couldn’t have received [B] ought to have received
[C] has received [D] shouldn’t have received
（答案为A）
3）may / might have +过去分词，表示对已发生的事情做不肯定、可能性很小的推测，或事实上根本没发生，译为“也许……”。如：
At Florida Power’s Crystal River plant, a potentially serious leakage of radioactive water may have been unknowingly caused by an electrician.
2．表示虚拟语气。
1) needn’t have + 过去分词，表示做了不必做的事，相当于”didn’t need to do”,译为“其实没必要……”。如：
You needn’t have come over yourself.
As it turned out to be a small house party, we so formally.
[A] needn’t dress up [B]did not need have dressed up
[C] did not need dress up [D] needn’t have dressed up
(没有必要穿的那么正式，体现是说话者的建议，实际结果是否真的穿的很正式没有确定，答案为D)
2）should have +过去分词，表示应该做某事但实际上未做，译为“本应该……”should not + have过去分词表示本不应该做某事但实际上做了，译为“本不应该……”。如：
I regret having left the work unfinished; I should have planned everything ahead carefully.
我本来应该事先认真地把每件事情规划的很好，但实际上作者还是没有规划好，以至工作没有完成。
3) ought to have +过去分词，表示动作按理该发生了，但实际上未发生，译为“该……”，与should 的完成式含义类似。如：
Ｔhe porter ought to have called the fire-brigade as soon as he saw the fire in the stock, which went up in smoke .
4) could have +过去分词，表示过去本来可以做但却未做，译为“完全可以……”。这点与ought/should/ have +过去分词用法相似。如：
What you said is right, but you could have phrased it more tactfully.
5) may/ might have +过去分词，表示过去可以做但实际未做，译为“（那样）也许会……”。如：
It might have been better to include more punchy statistics and photos of equipment in the introduction to further assist first-time office automation managers.
二．几个情态动词常考的句型：
1)．may/might (just) as well “不妨，最好”，与had better相近；
Since the flight was cancelled, you might as well go by train.
既然航班已经取消了，你不妨乘火车吧。相当于you had better go by train。
2) ．cannot / can’t…too …“越……越好，怎么也不过分”。注意这个句型的变体cannot…over….如：
You cannot be too careful when you drive a car.驾车时候，越小心越好。
The final chapter covers organizational change and development. This subject cannot be over emphasized .
3) ．usedn’t 或did’t use to 为used to (do) 的否定式。
4）．should 除了“应该”一层意思外，考研大纲还规定要掌握其“竟然”的意思。如：I didn’t expect that he should have behaved like that. 我无法想象他竟然这样做。
三．情态动词被动关系的主动表达法
1． want, require, worth（形容词）后面接doing也可以表示被动意义。
Your hair wants cutting
The book is worth reading
The floor requires washing.
2．need既可以用need to be done 也可以使用need doing ，两种形式都表达被动的意义
The house needs painting= the house needs to be painted.
The watch needed repairing= the watch needed to be repaired.
（二） 形容词、副词及比较级最高级
一．形容词的修饰与位置
一般来说，从构词法角度来看，后缀”ly”往往是副词，但有的以“ly’结尾的词是形容词而不是副词，这点要注意；形容词一般可以在句子中做定语，表语等成份，但有些形容词在句子中只能做表语和只能做前置定语；这些形容词在修饰时候有一定的特殊性要引起大家的注意，下面做了一下归纳：
1 以-ly结尾的是形容词而不是副词：
costly 昂贵的 lonely 孤独的 deadly 死一般的 lively 活泼的 friendly 友好的 silly 傻气的 kindly 热心肠的 likely 可能的 leisurely 悠闲的 ugly 长得丑的 brotherly 兄弟般的 monthly 每月的 earthly 尘世的
2 只作以“a”开头的很多形容词只能做表语：
afraid 害怕的 alike 相象的 awake 醒着的 alone 单独的，惟一的 alive 活着的 ashamed 羞愧的
asleep 睡着的 aware 意识到的、察觉到的 well 健康的 content 满意的 unable 无能的
3 只作前置定语的形容词
earthen 泥土做的，大地的 daily 每日的 latter 后面的 golden 金子般的 weekly 每周的 inner 里面的
silken 丝一般的 monthly 每月的 outer 外面的 wooden 木制的 yearly 每年的 elder 年长的 woolen 毛织的 former 前任的 mere 仅，只不过 only 惟一的 sheer 纯粹的 very 恰好的 little 小的 live 活的
4．下列动词既是实义动词又是系动词，注意用做系动词时，要求形容词做表语：
remain keep become, get, grow, go, come, turn, stay, stand, run, prove, seem, appear, look。
如：All those left undone may sound great in theory, but even the truest believer has great difficulty when it comes to specifics.
二．形容词与副词的比较级与最高级
1． 考比较级时，考生应把握：
1）形容词和副词比较级的形式是否和比较连词对应出现，即是否符合原级比较及比较级的结构。如：
Do you enjoy listening to records? I find records are often , or better than an actual performance.
[A]as good as [B]as good [C]good [D]good as
在这里as good as 比较连词与better than比较连词同时出现时候，不能省略任何一个介词。答案为A
On the whole, ambitious students are more likely to succeed in their studies than are those with little ambition.
2)比较的成分是否属于同类事物或同类概念，既是说比较要具有可比性。如：
The number of registered participants in this year’s marathon was half .
[A] of last year’s [B]those of last year’s
[C]of those of last year [D] that of last year’s
（前后相比的应该是今年和去年注册参加的人数“the number of”故代替它的应该是单数指示代词“that”，而不能选择B，those是指代participants，不是同类对比，答案为D。
Young readers, more often than not, find the novels of dickens far more exciting than Thackeray’s.
3)比较级与倍数词关系及其位置
原级结构中可插入表达倍数的词，表示为“为….若干倍”,当与有表示倍数比较的词在一起时候等，他们的位置是，倍数词+as…as…,或倍数词+more…than…，但again一般放在原级词之后，即 “as+原级＋again+as”.如：
Smoking is so harmful to personal health that it kills people each year than automobile accidents.
[A] seven more times [B] seven times more
[C] over seven times [D] seven times
(答案为B)
“Do you regret paying five hundred dollars for the painting?”“No, I would gladly have paid for it.”
[A] twice so much [B] twice as much
[C] as much twice [D] so much twice
(答案为B)
My uncle is as old again as I am
4）下列词和短语不用比较级形式却表示比较概念：
inferior, minor, senior, prior, prefer to, superior, major, junior, preferable, differ from, compared with, in comparison with, different from, rather than. 如：
Their watch is to all the other watches on the market.
[A] superior [B] advantageous [C] super [D] beneficial
（答案为A）
Prior to his departure, he addressed a letter to his daughter. (1986年考研题)
5）“比较级＋and +比较级”或“more and more/less and less +原级”以及“ever, steadily, daily等副词＋比较级”结构表示“越来越……”的意思，与这类结构搭配的常用动词有grow, get ,become等。前面两种情况更多地出现在进行时态中，注意的是这三种情况引导的比较级后面都不需要用than.如：
Things are getting worse and worse.
As I spoke to him he became less and less angry.
Her health was becoming daily worse
The road got ever worse until there was no road at all = the road got worse and worse.
6)比较级前面可以用even, still, yet ,all the (more)等修饰语用以加强语气，表示“更加”的意思。如
Today it is even colder than yesterday
I have yet more exciting news for you
7) 有关比较级的特殊句型：
A): not so much…as…与其说……不如说……
The chief reason for the population growth isn’t so much a rise in birth rates a fall in death rates as a result of improvements in medical care.
[A] and [B] as [C]but [D] or
人口增长的主要原因与其说是因为出生率的提高，还不如说是因为医疗的进步带来的死亡率下降的结果。答案为B
B) no/not any more…than…两者一样都不……
The heart is intelligent than the stomach, for they are both controlled by the brain.
[A] not so [B]not much [C]much more [D] no more
（心脏和胃两者都不具有智力，他们都受大脑控制。答案为D）
There is no reason they should limit how much vitamin you take, they can limit how much water you drink.
[A] much more than [B] no more than
[C] no less than [D] any more than
（答案为D）
C)no/not any less…than…两者一样,都……注意基本上与no/not any more…than意思相反
She is no less beautiful than her sister.她和她姐姐一样漂亮
D)just as… so… 正如……， ……也……（用倒装结构）
Just as the soil is a part of the earth, the atmosphere.
[A] as it is [B] the same is [C] so is [D] and so is
（答案为C）
2．最高级形式应注意的问题：
1）最高级比较范围用介词in, over, of, among。
in, (all) over用于在某一范围内的比较，如：in China, all over the world.
of, among用于在同一群体内同类事物的比较，如：among the teachers, of the four dresses.
注意：among…相当于one of …,不说among all…。这一点考生应与汉语表达区别开来
如：
all visible lights, red light has the longest and violet the shortest wavelength.
[A] Among [B] Of [C]For [D]To 答案为[B]
2)比较级形式表示最高级意义时，比较对象的范围应用：
any other +单数名词
the other +复数名词
the others
anyone/anything else
上述词是用业将比较级结构转变成最高级意义的关键词语，切不可遗漏，尤其是other，否则会造成逻辑混乱的错误。如不能说：John runs faster than anyone.注意与汉语表达的不同。
3）most可以用来修饰形容词或副词，意思相当于very，用法区分单复数，但不能用定冠词the，如：a most interesting book, most expensive restaurants， 要注意与 “the +形容词最高级＋of + 名词”的结构表示的最高级的区别，如：
He spoke in the warmest of voices
They have been most kind to me
Basketball is the most popular of sports in this country.
Chinese is the most difficult of language
Chinese is a most difficult language
