一、两者相比，甲=乙，用rtb“as +形容词或副词原级+ as”。如：
He is as tall as me.
He got up as early as I did.
二、两者相比，甲＜乙，用“not as/so+形容词或副词原级+as”dood。如：
He cannot run so/as fast as you.
Corn doesn’t need as/so much water as rice.
1、as…as结构的基本用法
其基本意思为“与……一样”，其中的第一个as副词，其后通常接形容词或副词(用原级)，第二个as可用作介词(后接名词或代词)或连词(后接从句)。使用时应注意以下几点：
（1）在否定句中，第一个 as也可换成 so：
He doesn’t study as [so] hard as his brother.
（2）两个as之间通常接形容词或副词的原级，但若涉及数量或程度，可用“as much+不可数名词+as”和“as many+可数名词复数+as”：
You’ve made as many mistakes as I have.
I haven’t got as much money as I thought.
（3）中间接形容词时，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)：当as…as中间有名词时，名词要放在形容词之后。如：
This is asgood an example as the other is.
I can carry asmuch paper as you can.。
She is as good a cook as her mother. （=She is a cook as good as her mother）
2、关于第二个as的词性
（1）第二个as后接从句时，该as通常为连词，但有时这个as还充当其后从句的主语或宾
语，此时该as实为关系代词。如：
I gave him as much as he could eat.
We’ve got food for as many people as want it.
（2）若第二个as用作连词引导一个表示将来意义的从句，则该从句可用现在时表示将来，也可直接使用将来时态。如：
We’ll get there as soon as you do [will].
3、as…as…结构的修饰语
该结构根据情况可用使用以下修饰语：(not) nearly, almost, just, nothing like, exactly, not quite, half, one-ten, twice, three times, 30 per cent等，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：
He doesn’t play half as well as his sister.
This dress is twice as expensive as that.
other是什么意思
4、as…as…结构的省略
（1）在非正式场合(尤其是美国英语中)，有时可以省略第一个as。如：
When over forty, he married a woman poor as himlf.
（2）若意思明确，有时可省略第二个as及其后的相关词语。如：
The pianos in that shop will be cheaper, but not as good.
三、两者相比，甲＞乙，用“比较级形容词或副词+ than”。如：
You are taller than me.
He reads more careful than me.
（more…than…的用法）
1、表示“比……更多”：此时more为many或much的例如用英语怎么说比较级，表示数量，后接名词。如：
I made more mistakes than you.
Last year there were more births than deaths.
He’s got more money than the rest of us together.
注：若more受much或many修饰，则分别与不可数和可数名词连用。如：
His car cost much more money than mine.
There are many more people than we expected.
2、表示“比…更”：此时more后接多音节形容词或副词，构成比较级，表示对两者进行比较。如：
He is more careful than the others.广州mba辅导班
Travelling by train is more relaxing than driving.
This company is more concerned with quality than with quantity.
3、表示“与其说……不如说”：此时不是对两个对象进行比较，而是对同一个人或物在两个不同方面进行比较或取舍，此时不论形容词或副词是单音节、双音节还是多音节，一律用more…than…。如：
He is more lucky than clever.
He was more frightened than hurt.
It is more grey than brown.
He is more (a) scholar than (a) teacher.
四、多者比较，用“the+最高级+比较范围”。如：
Tom is the tallestin his class.
whiteflagKate wrote (the) most carefully of all.
五、比较等级的特殊句型
1、新托福less/least +原级：表示降级的比较级或最高级。如：
I am even less lucky.
This is the least uful of the four books.
2、the+比较级, the+比较级：表示后者随着前者的变化而变化，意为“越……就越……”；前者相当于一个条件句，因此，要用一般现在时代替一般将来时。如：
The harder you work, the better result you’ll get.
3、the+比较级(+of the two)：表示“两者中较……的那个人或物”。如：
Tom is the taller of the two brothers.
4、比较级+and+比较级：表示“越来越……”，单音节形容词或副词用“-er+and +-er”，如：
warmer and warmer越来越暧和；
多音节形容词或副词用“more and more…”如more and more beautiful越来越美。
5、比较级+than any other+单数名词：表示最高级意义。如：
Mike is more intelligent than any other student in his class.(=Mike is the most intelligent in his class.)
6、否定词语+比较级：表示最高级含义。如：
Nothing is easier than this.(=This is the easiest thing.)
（注意：关于“never+比较级”结构）
否定副词never与比较级连用有时可表示最高级的意义。如：
I have never drunk better beer.
I have never met a kinder man.
He had never spent a more worrying day.
注：有时也可不用never而用其他否定词。如：
No news could be more delightful to me.这消息最令我高兴。
7、否定词语+ so…as：表示最高级含义。如：
Nothing is so easy as this.没有比这更简单的了。
8、no +比较级+ than：表示对两者的否定，意为“和…一样不…”；“not+比较级前+than”表示前者不如后者。如：
guojiaxian
Tom is no taller than Mike.
=Neither Tom nor Mike is tall. =Tom is as short as Mike.
Tom is not taller than Mike.
（注意：not more than和no more than的区别）
（1）not more than是more than的否定式，more than意为“多于”，所以not more than的意思就是“不多于”“不超过”；
（2）no more than主要强调more的反面，即强调数量之少或程度之低，其意为“只有”，如He gave no more than five dollars，其意为“他只给我5美元”。
因为同样的道理，我们可以推知，no less than强调的是less的反面，即强调多，如no less than 10 days，意为“多达10天”。比较：
再看所涉及的几个结构的意思：
not more … than =不如……
剑桥商务英语中级
no more … than =和……一样不(否定两者)
not less … than =不如……不（即指不如 less后形容词的反面）
no less … than =和……一样(肯定两者)
比较以下各句的意思：
You are more careful than he is.你比他仔细。
You are not more careful than he is.你不如他仔细。
六级评分You are no more careful than he is.你和他一样不仔细。
You are less careful than he is.你不如他仔细（你比他粗心）。
You are not less careful than he is.你比他仔细（你不如他粗心）。
You are no less careful than he is.你和他一样仔细。
