用于一对物体的分配词
分配限定词 both丶either 和 neither 论及的是一对物体的分配。一般来说，这些字词不能用来谈论任何超过两个个体的群体，也不能用来指不定大小的群体，只能用来论及可数名词。
both 的用法
both 同时指一对事物，相当于「其一和另一」。both 可以接复数名词，或者接 of +（定冠词）+ 复数名词。当 both 后面要接一个复数代词时，一定要在中间加上 of 来隔开。both 不能接单数名词，因为这个分配词涉及的是两个物体。
举例
- Both children were born in Italy.
- Both the children were born in Italy.
- Both of the children were born in Italy.
- Both my parents have fair hair.
- Both of my parents have fair hair.
- Both of us like skiing.
- I told both of them to calm down.
either 的用法
either 用于肯定句。当单独使用时，指的是两者整体，意思相当于「其一或另一」。由于 either 指的只是两者之间的其中一者，就必须接单数名词。但如果后面接了 of，则可以接复数名词或复数代词。
举例
- I can stay at either hotel.
- Either day is fine for me.
- There are two chairs here. You can take either of them.
- Either of you can come.
- Either of the hotels will be fine.
- I can eat either of the salads.
当依次谈到两件事物，就可以用 either... or... 的句型。这种结构并不会改变意思，但在此种情况下，either 的作用就不是分配词，而是连接词。
举例
- You can have either ice cream or chocolate cake.
- I will come on either Thursday or Friday.
- You can either come inside or put on your raincoat.
neither 的用法
neither 用于否定句。当单独使用时，指的是两者整体，意思相当于「不是其中一个也不是另外一个」。由于 neither 指的只是两者之间的其中一者，因此必须接单数名词。但如果后面接了 of，就可以接复数名词或复数代词。
举例
- Neither chair is any good.
- Neither brother came.
- Which bag do you want? Neither of them.
- Neither of us were on time.
- I think neither of these dresses fits me.
- Neither of the children wanted to go.
当依次谈到两个事物时，就可以用 neither... nor... 的句型。这种结构并不会改变意思，但在此种情况下，neither 的作用就不是分配词，而是连接词。
举例
- You can have neither cookies nor candy.
- It is neither raining nor snowing.
- She is neither tall nor short.