分配限定詞 half 用來談論一個劃分為二的群體，在用作分配詞的形式有很多種。其它部分也可以用於相同的形式，只是較為少見。
half 後可以接不定冠詞（a 或 an）為首的測量單位，在這種用法上，分配限定詞為一種測量法。
- I had half a cup of milk left.
- I bought half a kilo of flour.
- He ran half a mile this morning.
- I will be back in half a minute.
half 可以接名詞，但兩者之中必須夾帶定冠詞、不定冠詞、指示代名詞或所有格代名詞。在這種情況下，它指的是一個具體、實質上的劃分。而 half 接 of 並不會改變意思。
- Half the people have already left.
- Half of an apple isn't very much lunch.
- Did you use half my sugar?
- I will need half of the flour for my cake.
- I earned half of that money last summer.
- She found half these frogs in the river.
- I spent half that time on my project.
- You can take half of those books back.
- I've invited half my friends to the party.
- I've used up half of our eggs.
- You wasted half your money on that!
half 後可以接 of + 複數代名詞。
- Half of us are going.
- He scolded half of you but he let the rest off.
- You couldn't find half of them?