a |an1 指一类人或事，相当于a kind of .
A plane is a machine that can fly. 2 第一次提及某人某物，非特指。 There is a tree in my garden.
3 用于人名前，表示不认识此人或与某名人有类似性质的人
或事. — Hello, could I speak to Mr. Smith? —Sorry, wrong number. There isn't______ Mr. Smith here. A. 不填 B. a C. the D. one 4 用于抽象名词具体化的名词前
success(抽象名词)→a success(具体化) 成功的人或事 a failure 失败的人或事 a shame 带来耻辱的人或事 a pity 可惜或遗憾的事 a must 必需必备的事 5 用于quite, rather, many, half, what, such之后. This room is rather a big one.
the1 表示某一类人或物.
In many places in China,thebicycle is still a popular means of transportation.
2 表示说话双方都了解的或上文提到过的人或事.
Bring me the book, please.
3 用于世上独一无二的事物名词前.
The moon, the earth…
4 用于序数词和形容词副词比较级最高级前
He is the taller of the two children.
5 用于国家党派等以及江河湖海，山川群岛的名词前
French.
the United States, the Communist Party of China, the
6 表示“一家人”或“夫妇”.
—Could you tell me the way to the Johnsons, please? —Sorry, we don’t have aJohnson here in the village.