a /æn, æn/ (also an) CET4

• 1. 

  DET You use a or an when you are referring to someone or something for the first time or when people may not know which particular person or thing you are talking about. (用于首次提及或泛指某人或某物) 一 (个)

  例：

  A waiter entered with a tray bearing a glass and a bottle of whisky.

  一名服务员端着一个放有一只玻璃杯和一瓶威士忌酒的托盘进来了。

  例：

  He started eating an apple.

  他开始吃苹果。

• 2. 

  DET You use a or an when you are referring to any person or thing of a particular type and do not want to be specific. 用于指一类人或物，不需要特指

  例：

  I suggest you leave it to an expert.

  我建议你把它留给专家来处理。

  例：

  Bring a sleeping bag.

  带个睡袋来。

• 3. 

  DET You use a or an in front of an uncount noun when that noun follows an adjective, or when the noun is followed by words that describe it more fully. 一种 (用于前有形容词或后有修饰语的不可数名词前)

  例：

  The islanders exhibit a constant happiness with life.

  这些岛民表现出一种对生活的持久的幸福感。

• 4. 

  DET You use a or an in front of a mass noun when you want to refer to a single type or make of something. 一种 (用于物质名词前，特指某物的种类或成分)

  例：

  Bollinger "RD" is a rare, highly prized wine.

  是一种罕见的、非常名贵的葡萄酒。

• 5. 

  DET You use a in quantifiers such as a lot, a little, and a bit. 用在量化词组中，如(a lot), (a little), (a bit##bit)等

  例：

  I spend a lot on expensive jewellery and clothing.

  我在昂贵的首饰和衣服上开销很大。

• 6. 

  DET You use a or an to refer to someone or something as a typical member of a group, class, or type. 指某人或某物是一个团队、阶层或类型中典型的一员或一部分

  例：

  Some parents believe a boy must learn to stand up and fight like a man.

  一些家长认为一个男孩必须学会像男子汉一样奋起战斗。

• 7. 

  DET You use a or an in front of the names of days, months, or festivals when you are referring to one particular instance of that day, month, or festival. 用于某一天、某一月份或某节日前，特指在该天、该月或该节日发生的事件

  例：

  The interview took place on a Friday afternoon.

  该面谈是在一个星期五下午进行的。

• 8. 

  DET You use a or an when you are saying what someone is or what job they have. 用于说明某人的职业

  例：

  I explained that I was an artist.

  我解释说我是一位艺术家。

• 9. 

  DET You use a or an instead of the number "one," especially with words of measurement such as "hundred," "hour," and "metre," and with fractions such as "half," "quarter," and "third." 一 (代替)(one)

  例：

  ...more than a thousand acres of land.

  …一千多英亩的土地。

• 10. 

  DET You use a or an in expressions such as eight hours a day to express a rate or ratio. 每一 (用于速率或比率的表达中)

  例：

  Prices start at $13.95 a yard for printed cotton.

  印花棉布开价为$13.95一码。

• 11. 

  V → an informal or dialect word for have

  例：

  they'd a said if they'd known

• 12. 

  PREP → (usually linked to the preceding noun) an informal form of of

  例：

  sorta sad

  例：

  a kinda waste

• 13. 

  SYMBOL for acceleration 加速度