用法：
1. 與具體數字連用時，不加復數詞尾 –s；若后接名詞，通常也無需用介詞of。如：
He bought three dozen bottles of wine.他買了36瓶酒。
He has lived here for two score years. 他已在這兒住了40年。
2.偶爾也可見到受具體數字修飾的dozen, score后接 of，但慣用法認為省略 of則常見。
3. dozen可用作量詞, a dozen of修飾名詞時of可省略,但dozens of中的of不能省去。
There were dozens of people there. 那里有許多人。
I have heard of that scores of times. 那件事我已聽過很多遍了。
4. 當與a few, several, many等數目不很具體的詞連用時，帶不帶復數詞尾 -s均可，但是注意：若不帶復數詞-s，其后的介詞of可以省略；若帶復數詞尾-s，則其后介詞of不能省略。
several dozen(s) of eggs=several dozen eggs 幾打雞蛋
several dozen (of) pencils= several dozens of pencils 幾打鉛筆
5. 若其后的名詞受the, these, those等特指限定詞的修飾，或其后接的是us, them 這樣的人稱代詞時，則此時必須用介詞of。如：
I had bred a dozen of chickens.
我飼養了12只小雞。
There were about a dozen of them.
大約有十二人。
6.用作形容詞，表示一打的，十二個的。
My mother bought a dozen eggs.
我媽媽買了一打雞蛋。
They began by baking two dozen loaves.
他們通過烘烤兩打的面包開始。