知识的宽度、厚度和精度决定人的成熟度。每一个人比别人成功，只不过是多学了一点知识，多用了一点心而已。下面小编给大家分享一些大学英语四级知识，希望能够帮助大家，欢迎阅读!
大学英语四级知识1
as…as
1.基本用法
该结构的基本意思是“与……一样”，其中接形容词或副词的原级，在否定句中，第一个as也可换成so.如：
He doesn't study as [so] hard as his brother. 他学习不如他弟弟努力。
2.涉及数量或程度的用法
若涉及数量或程度，可用“as much+不可数名词+as”和“asmany+可数名词复数+as”。如：
He doesn‘t pay as much tax as we do / as us. 他没我们交的税款多。
There are not as many restaurants as there were. 现在餐馆没有过去多了。
3.有关词序的一点说明
其间接形容词时，有时该形容词还可修饰另一名词，但这个名词应带有不定冠词(注意词序)。如：
I have as good a voice as you. 我的声音和你一样好。
4.该结构的修饰语
根据情况可用(not) nearly, almost, just, nothing like, exactly, not quite, half, one-ten, twice, threetimes, 30 per cent等修饰，并且这些修饰语必须置于第一个as之前，而不能置于其后。如：
This room is twice as large as that one. 这个房间是那个房间的两个大。
You‘re not half as clever us you think you are. 你远不是自己想像的那么聪明。
It took three times as long as I had expected. 这件事比我预料的多花了两倍的时间。
大学英语四级知识2
first & at first
1、从词性上看区别
first可用作形容词或副词，有时还可用作代词;而at first作为介词短语，只起副词用作用(在句中用作状语)。如：
First class is the most expensive way to travel. 坐头等舱是最贵的旅行方式。(first为形容词，在句中用作定语)
This is the first time I have heard of such things. 这是我第一次听到这样的事。(first为形容词，在句中用作定语)
You needn‘t read the whole book hut you must readthe first four chapters.你们不必把整本书全读完，但必须读完前四章。(first为形容词，在句中用作定语)
I asked them to ring first in case we were out. 我请他们先打电话来，以防我们不在家。(first为副词，在句中用作状语)
She‘s always the first to arrive and the last to leave. 她总是第一个来，最后一个离开。(first为代词，可视为其后省略了one， person等之类的词)
His second suggestion was not much better than his first. 他的第二个建议比第一个好不了多少。(first为代词，可视为其后省略了suggestion)
At first we used hand tools. Later we had machines. 开始我们用手工工具，后来我们有了机器。(atfirst在此用作状语)
2、从用法上看区别
1).first的用法
first 用来说明顺序，意为“先……”，暗示接下去还有其他动作或事件要发生，因此其后往往接有(或暗示有)then，next，last 等词。如：
Think first, then act. 先想清楚再行动。
I‘ll have to finish my homework first. 我得先把作业做完。
First, boil some water. Then, warm the teapot. Then, add three teaspoons oftea. Next, pour on boiling water… 你先烧些开水，然后把茶壶烫热，接着放三勺茶叶，随后冲入开水……
John came home from work. First he read the paper for a while, then he got up from the chairand turned on the radio. 约翰下班回家，先看一会儿报，然后从椅子上站起来，打开收音机。
2). at first 的用法
at first 的意思是“起初”“开始”，它主要用于强调前后对照，暗示接下去的动作与前面的动作不同甚至相反，因此常有 but，afterwards，soon，at last等相呼应。如：
At first I didn‘t want to go, but I soon changed my mind. 我开始不想去，但我很快就改变了主意。
The work was hard at first, but I got used to it. 起初这活儿很累，不过后来我习惯了。
At first they were very happy, but then things started going wrong. 起初他们生活得很幸福，但后来就开始出问题了。
At first I paid little attention, but slowly my interest awoke. 起初我没怎么注意，但逐渐产生了兴趣。
3、其他几点区别
1). at first 除以上用法外，其他场合一般不用它;而first除表示“先……(然后……)”外，还可表示“最先”“第一次”“首先”等。如：
Ladies first. 女士优先。
That‘s mine—I saw it first. 那是我的，是我先看见的。
When did you first meet him? 你第一次见他是什么时候?
2). 有时at first并非固定搭配(first后还修饰有其他词语)。如：
She was so nice a girl that he fell in love with her at first sight. 她是这样好的一个姑娘，使他一见钟情。
She could tell at first glance to which class a man belonged. 她一眼就能看出一个人属于哪个阶级。
3). at first与at last不是一对反义词组，后者的意思是“终于”“最终”。如：
At last the truth became known. 最后真相大白了。
She has at last got everything ready. 她最后把一切准备好了。
At last the bus came. I had been waiting for half an hour. 最后公共汽车来了，我已等了半小时。
大学英语四级知识3
angry
1.表示“对某人生气”，一般用介词 with(有时也用 at)
The teacher got angry with [at] me. 老师对我生气了。
有的词书认为：用with表示心中感到生气，而用at则表示怒气流露于外表，但总的说来此时还是用with的场合较多。
2.表示“对某事生气”，一般用介词 at(about)
He was rather angry at what you said. 他对你说的话相当生气。
I was angry about missing the film. 没看上那部电影我很气恼。
有的词书认为：at 之后接某人之言行，about 之后接某事，但这种区别并不十分严格，两者常可换用。
3.表示生气的原因，一般用介词for
He was angry with me for not having done anything. 因为我什么也没做，他对我很生气。
注：be angry 之后除搭配介词外，还可接不定式或从句：
He‘ll be angry to find that nothing has been done. 他发现什么都没做，他会生气的。
He was angry that the door was locked. 门锁上了，他很生气。
大学英语四级知识4
able
1.表示“有能力的”、“能干的”，可用作表语或定语。如：
He is an able manager. 他是位有能力的经理。
He is old but still able. 他虽年老，但仍有很能干。
2.用于 be able to do sth(能或会做做某事)。如：
He is able to speak English. 他会说英语。
Everyone here is able to type. 这儿的每一个人都会打字。
He will be able to get about in a week or two. 再过一两个星期左右他就能走动了。
He studied hard and was able to pass his examinations. 他学习很努力，所以考试及了格。
注：be able to 不仅有多种时态形式(通常不用于进行时或与 be going to 连用)，而且还可以与某些情态动词连用(通常不与 can 连用)，甚至还可以有非谓语形式。如：
Since his accident he hasn't been able to leave the house. 自出事之后，他一直未能离开家。
You might be able to persuade him. 你也许能够说服他。
I hope to be able to do the work. 我希望能干得了这项工作。
I regret not being able to help her. 我很遗憾未能帮助她。
3.able 的比较级和最高级通常是abler和ablest，也可以是more able和most able，有时还可用 betterable和best able.如：
You are better able to do it than I (am). 你比我更有能力做这件事。
She's the person best able to cope. 她是个最能妥善处理问题的人。
4.若要加强语气，其前除可very，quite，perfectly等修饰外，有时还可用well修饰。如：
He is quite [well] able to take care of himself. 他完全有能力照顾自己。
He's a very able student; he's just too lazy. 他是个很有能力的学生，只是太懒了。
若受just，only just修饰，则表示“只能”“仅能”。如：
I was just able to make out a dark figure in the distance. 我只能看见远处有个黑影。
5.able的反义词是unable(不能的，不会的)，不是disable，后者是动词，其意为“使残废”“使无能力”。比较：
They were unable to reach a decision. 他们没法做出决定。
Now that he was disabled, his house had become a prison to him. 因为他残废了，他的房子就成了他的牢笼。
大学英语四级知识5
hundred，thousand &million
(1) 用单数的场合
当这些词与具体数字连用时，习惯上用单数，而且也不后接介词of.如：
He was prepared to pay two million. 他愿意支付200万。
More than a hundred people were injured. 有一百多人受了伤。
但是，当这些词后面的名词有了the，these，those等特指限定词修饰时，或其后的接的是us，them 这样的人称代词时，则此时必须用介词of.如：
About three hundred of them have left there. 他们当中约有300人离开了那儿。
(2) 用复数的场合
当这些词不与具体数字连用，而是表示不确定的泛指数时，则不仅要要用复数，而且要后接介词of，然后才能接名词。如：
The sun was shining. Thousands of people were lying on the beach. 阳光灿烂，数以千计的人躺在海滩上。
A careless mistake cost the company millions of pounds. 一个粗心的错误使公司蒙受数百镑的损失。
大学英语四级知识点