形容词原级
英文中形容词有三个比较等级，因此，形容词有原级的用法、比较级的用法和最高级的用法。
1. 形容词的原级的用法主要是用于两者之间程度是否相同的比较。
2. 肯定形式用as+原级形容词+as+比较成分，表示“和...一样”。
Tom is as tall as I (am).
汤姆和我一样高。
And I am as fat as you (are).
而且我和你一样胖。
The temperature is as high as (it was) yesterday.
今天的温度和昨天一样高。
3. as much/many...+ as... 表示前后数量相同。
I had just as many bones as you did.
我和你吃的骨头一样多。
4. 否定形式用 not so (as)+原级形容词+as+比较成分，表示“不如...”。
Our hosts are not so nice as those of other dogs.
我们的主人不像其他狗的主人那样好。
Jane is not so (as) tall as I (am).
珍不如我高。
We don't look so strong as that guy.
我们看起来没有那家伙壮。
5. as+形容词原级+as+用作比喻的名词，此结构形成了许多惯用语，多用于口语。
There! There! You are as hungry as a bear.
瞧！瞧！你饿得像只熊。
My God! It is as hard as a rock.
天啊！它硬得像块岩石。
形容词比较级
1. 表示“比...更”，用比较级形容词+than+比较成分，表示前者“超过”后者。than后悉滚主语的述语动词往往省略，非正式用法的than后的人称代名词可用宾格。
I am a better swimmer than you (are).
我游泳比运陆桥你好。
But you are taller and stronger than I (am).
但是你比我高，比我壮。
Just because you are shorter and weaker, is that the reason you become a slower swimmer than me?
仅仅因为你比我矮比我弱，就有理由比我游得慢吗？
2. 否定的比较级表示“较...低；不及...”，用less+原级形容词+than+比较成分，表示前者不及后者。
I have always tried to help those who are less fortunate than I.
我一旁猛直设法帮助比我不幸的人。
At least you are less generous than I.
至少你没有我慷慨。
3. 表示两者之中“较...”，用the+比较级+of the two。
I'll give you the bigger of the two steaks; I'm not very hungry.
我要把这块比较大的牛排给你，我不怎么饿。
4. 定冠词或指示形容词+比较级+名词表示比较。
The taller man is the boss of the restaurant and the shorter one is his brother.
那个身材较高的男人是餐馆老板。较矮的那位是他弟弟。
5. 有少数以-ior结尾的属于拉丁语的形容词，如inferior(次于), junior(年幼的;下级的), posterior(之后), prior(之前), senior(年长的,上级的), superior(优于)等本身就有比较的意思，后面不接 than，常与介系词to连用，后面用宾格。
I am two years junior to you.
我比你小两岁。
该句相当于?
I am two years your junior.
I am your junior by two years.
I am two years younger than you (are).
类似结构还有?
be senior to(年长于)+宾格 ?be older than+主格
be superior to(优于)+宾格 ?be better than+主格
be inferior to(劣于)+宾格 ?be worse than+主格
6. 比较形容词可以被修饰语如a little(一点), much(得多), even(更加), still(更加), far(...得多), very much, any, no, rather, a lot (a great deal), a little (a bit)等修饰，但不可用very修饰，表示某种程度。
The sun is a lot bigger and brighter than the moon.
太阳比月亮大得多、亮得多。
形容词最高级
用于三者或三者以上的比较时,“最...”的要用最高级形容词，最高级前一般要加the，并有介系词片语、子句或所有格表示比较范围。
I am the tallest in our class.
我是咱们班里个子最高的。
表示在某一场所中最...,和in引导的介系词片语连用。
My movements are the most graceful of us three.
三个人中我的动作是最优雅的。
表示在不少于三者的同类中“最...”,和of或among引导的介系词片语连用。
Racing is the most interesting sport I've ever known.
赛跑是我知道的最有趣的运动。
表示在已有的经验中“最...”,子句表示比较范围。
You are always my fondest star.
你永远是我最喜欢的明星。
用代名词的所有格表示比较范围。
the+最高级+比较范围
1) The Sahara is the biggest desert in the world.
形容词最高级前通常必须用定冠词 the，副词最高级前可不用。
形容词most前面没有the，不表示最高级的含义，只表示"非常"。
It is a most important problem.
=It is a very important problem.
注意： 使用最高级要注意将主语包括在比较范围内。
(错) Tom is the tallest of his three brothers.
(对) Tom is the tallest of the three brothers.
2) 下列词可修饰最高级，by far， far， much， mostly， almost
This hat is nearly / almost the biggest.
注意：
a. very可修饰最高级，但位置与much不同。
This is the very best.
This is much the best.
b. 序数词通常只修饰最高级。
Africa is the second largest continent.
3) 句型转换：
Mike is the most intelligent in his class.
Mike is more intelligent than any other students in his class.
4) "否定词语+比较级"，"否定词语+ so… as"结构表示最高级含义。
Nothing is so easy as this.
=Nothing is easier than this.
=This is the easiest thing.
