97　all, both和each

1　all 意为“都”，强调整体，与复数名词连用时，指三者或三者以上。all 还可以同单数可数名词或不可数名词连用。

We are all Chinese. 我们都是中国人。

All horses are animals. 所有的马都是动物。

I wandered in the hills all afternoon. 我整个下午都在山里漫游。

2　both 意为“两者都”。

They are both in Grade Three. 他们两人都是3年级 。

Both of them are in Grade Three.

3　all 和both 都可以与限定词the, these, my, your等连用。

All their houses were burned down. 他们所有的房屋都烧毁了。

Both these rooms are not big enough. 这两个房间都不够大。

4　each 意为“每一”，强调个别，指个体。

Each of them has a pen. 他们每人都有一支钢笔。