冠词

二、不定冠词的用法

1、不定冠词用来表示“一”这个数量，意思和one差不多：

Rome was not built in a day.罗马不是一天建成的。

He will be back in a day or two.他将在一至两天内返回。

A stitch in time saves nine.及时一针顶十针。

这种用法在表示重量、长度、时间等的词组中特别普遍。例如：a pair of socks, a hundred, two yuan a metre, eight hours a day, twice a week, a cup of tea, in a word, one at a time.

2、表示人或事物的某一类

A steel worker makes steel.

A plane is a machine that can fly.

A teacher must love his students.

A knife is a tool for cutting with.

3、表示某一类人或事物中的任何一个。

This is an apple.

His father is a teacher.

This poem was written by a student.

She picked up a magazine and began to read.

4、用于泛指人或者事

The peasant girl has now become an engineer.这个农村姑娘现在成了工程师了。

She wanted to rent an apartment near the campus.　她想在学校附近租一套房子。

Before she left for London, Sally sent me a picture of herself. 萨莉动身去伦敦前送给我一张她的照片。

A grammar book is necessary to a language learner. 对语言学习者来说，语法书是很必要的。