用於一對物體的分配詞
分配限定詞 both、either 和 neither 論及的是一對物體的分配。一般來說，這些字詞不能用來談論任何超過兩個個體的群體，也不能用來指不定大小的群體，只能用來論及可數名詞。
both 的用法
both 同時指一對事物，相當於「其一和另一」。both 可以接複數名詞，或者接 of +（定冠詞）+ 複數名詞。當 both 後面要接一個複數代名詞時，一定要在中間加上 of 來隔開。both 不能接單數名詞，因為這個分配詞涉及的是兩個物體。
舉例
- 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 用於肯定句。當單獨使用時，指的是兩者整體，意思相當於「其一或另一」。由於 either 指的只是兩者之間的其中一者，就必須接單數名詞。但如果後面接了 of，則可以接複數名詞或複數代名詞。
舉例
- 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.
當依次談到兩件事物，就可以用 either... or... 的句型。這種結構並不會改變意思，但在此種情況下，either 的作用就不是分配詞，而是連接詞。
舉例
- 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 用於否定句。當單獨使用時，指的是兩者整體，意思相當於「不是其中一個也不是另外一個」。由於 neither 指的只是兩者之間的其中一者，因此必須接單數名詞。但如果後面接了 of，就可以接複數名詞或複數代名詞。
舉例
- 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.
當依次談到兩個事物時，就可以用 neither... nor... 的句型。這種結構並不會改變意思，但在此種情況下，neither 的作用就不是分配詞，而是連接詞。
舉例
- You can have neither cookies nor candy.
- It is neither raining nor snowing.
- She is neither tall nor short.