不定冠词（indefinite article）或限定词（determiner）
1.用于提及之前没有提到过的或面向的听众不知道的某人或某事
We have a problem.
There was a hole in the fence.
Suddenly they heard a loud bang.
2.用于指称总的一类人或物
Would you like a sandwich?
I want to train to be an engineer.
It needs a good clean.
3.用于某人的姓（family name）前以表示其归属于某家族
One of his daughters had married a Rothschild.
4.“一”（one）
a thousand pounds
a dozen eggs
You'll have to wait an hour or two.
5.用于某些短语中显示某物的数量
There were a lot of people at the party.
A few weeks from now I'll be in Venice.
You have caused a great deal of trouble.
6.用于说明价格、比率或速度时意义等同于“每”（each）
I get paid once a month.
The eggs cost＄2 a dozen.
7.用于单数名词前，意指所有的某一特定种类的事物
A square has four sides.（=all squares have four sides）
A child needs love and affection.
8.用于两个经常被一起提到的名词前
I'll fetch you a cup and saucer.
Does everyone have a knife and fork?
9.用于动词ing形式前，指代某一动作、事件或声音
There was a beating of wings overhead.
Bernice became aware of a humming that seemed to come from all around her.
10.用于由形容词、短语或从句等给出有关状态、情感等的其他信息的通常为不可数的名词前
Candidates must have a good knowledge of chemistry.
11.用于某一物质、食物等的名称前以指称某一特定类型的该事物
Use a good cheese to make the sauce.
plants that grow well in a moist soil
12.用于某一饮品的名词前以指称“一杯”该饮品
Can I get you a coffee?
13.用于著名艺术家的名字前以指称该艺术家的一幅画
an early Rembrandt
14.用于某一名字前以显示某人或某物具有该名字指称的某人或某物的相同的特点
She was hailed as a new Marilyn Monroe.
15.用于某个你不知道是谁的人的名字前
There is a Mr Tom Wilkins on the phone.
16.用于日期、月份、季节或事件的名字前以指称某特定的一个
We arrived in England on a cold wet Sunday in 1963.
I can't remember a Christmas like that.