both的用法

Both:adj、两个的,两者的
adv、并,又,两者都
pron、双方都,两者都
conj、既…且
①both表示两者都…,有多种词性。

例:
副词:We are both students、
代词:The brothers are good at playing basketball、Both will take part in the game、形容词:Both (the) instruments are valuable to this process、
连词:Both copper and silver are good conductors of electricity、
铜与银都就是良好的导电体。

②它的否定形式就是neither,词性与both一样,例:
We are neither student、
Neither of us is a student、= Either of us is not a student、
③Both可以与名词、代词连用,也可以与动词连用,在句子中做主语、宾语及同位语,也可以做定语。

1）both与名词、代词连用
both + (of) +the/物主代词/指示代词/ + 名词
Both of the cats are asleep、
I bought both of these bottles in China two years ago、
Both of his daughters are doctors、
在人称代词前一定要用both of,不能说both we, both us, 但可以说us both, them both、
Both of us like skating,
I want both of them、
2）both直接修饰名词,不加of
Both children won prizes、
注意:不能说both of children,可说both of the children
I’ve got oil on both hands、
注意:不能说both of hands, 可说both of my hands、
④当both在句中作主语的同位语时,也可以与动词连用,both在句中的位置通常用于be动词、助动词或情态动词之后, 实义动词之前。

1）放在be动词之后
The children are both lovely、
They are both from Australia、
注意:在感叹句或者简略答语中,both应该置于be之前。

How beautiful they both are!
--Are you both from Japan?
--Yes, we both are、
2)放在行为动词前
We both like watching TV、
They both want to go shopping、
3）当谓语动词就是由几部分组成时,both要放在第一个助动词后面We have both studied acting、
The rooms have both been cleaned、
⑤both做代词,可单独使用,其后不接名词
The brothers are good at playing basketball、Both will take part in the game、
--Which one do you want?
--I'll take both please、
注意:both与not连用,就是部分否定
Both the doors are not open、
⑥both…and…两者都,能连接各种并列成分。

Both Mary and Tina are girls、(连接两个主语)
If you are success, you can get both money and power、(连接两个宾语)
These books are both interesting and helpful、(连接两个表语)
It is necessary to build a lot of petrochemical works, both because of China is rich
in petroleum and because there is a great demand for petrochemicals、(连接两个状语从句)。