too， as well 和 also 用于肯定句和疑问句，

too 和 as well 多用于口语，一般放在句末，

also 多用于书面语，一般放在句中与动词连用。

either 用于否定句和否定的疑问句，往往放在句末。

他也去了。   He went there too

他没有去那儿。  He didn't go there either

我喜欢你。   I like you as well

我也去那里。   I also went there

形容词与副词的比较级其用法与形容词相似，只是副词最高级前可省略定冠词。

所有的男孩他唱得最动听。   of all the boys he sings most beautifully

我们必须更加努力地工作。   We must work harder

as +形容词或副词原级+ as。

在否定句或疑问句中可用 so    as 。

他不能和你跑得一样快。   He cannot run so fast as you

as +形容词+ a +单数名词

as + many  +名词

as + much +名词

这是和另一个一样好的例子。   This is as good an example as the other is

我可以携带尽和你一样多的纸   I can carry as much paper as you can

用表示倍数的词或其他程度副词做修饰语时，放在 as 的前面。

这个房间是那个房间的两倍。   This room is twice as big as that one

你的房间和我的一样大小。   Your room is the same size as mine

 倍数+ as + 形容词+ as

倍数+ than + of

这座桥是那座桥的三倍长。   This bridge is three times as long as that one

 ###  This bridge is three times the length of that one

你的房间是我的两倍大。   Your room is twice as large as mine

 ###  Your room is twice the size of mine

比较级形容词或副词+ than

你比我高。   You are taller than I

他们在你的房间灯一样亮。   They lights in your room are as bright as those in mine

要避免重复使用比较级。

他比他弟弟聪明。   He is more clever than his brother   

 ###  He is cleverer than his brother

要避免将主语含在比较对象中。

中国比亚洲其他国家都大。   China is larger than any other countries in Asia

要注意对应句型，遵循前后一致的原则。

上海的人口比北京多。   The population of Shanghai is larger than that of Beijing

制定一个计划比执行它更容易。   it is easier to make a plan than to carry it out

要注意冠词的使用，后有名词的时候，前面才有可能有冠词。

 哪个国家比较大 加拿大还是澳大利亚  Which is larger , Canada or Australia ?

 ###  Which is the larger country， Canada or Australia?

她比她两姐妹高。    She is taller than her two sisters

她是两姐妹中较高的。  She is the taller of the two sisters

可修饰比较级的词a bit,   a little,    rather ,   much,    far,    by far,    many,    a lot,    lots ,   a great deal,    any ,   still ,   even ,   等

还可以用表示倍数的词或度量名词作修饰语。

 除 by far , 外，必须置于比较级形容词或副词的前面。

保持头脑清醒要好得多。  It was better by far to be clear-headed

 any 可修饰比较级，

quite 修饰原级，

well 的比较级为 better

much 可修饰比较级，

 much more +不可数名词

 many more +可数名词复数

old 有两种比较级和最高级形式: older , oldest ,和 elder ,eldest 。

 elder , eldest, 只用于兄弟姐妹的长幼关系。

我的哥哥是一名工程师。   My elder brother is an engineer

玛丽是三姐妹中的老大。   Mary is the eldest of the three sisters

far 有两种比较级， farther , further 在英语中两者都可指距离。

在美语中， farther 表示距离， further 表示进一步。

我没有什么进一步说的。   I have nothing further to say