a与an的用法详解
 
【用法归纳】
1.一(个，件，…)：
He had a book under his arm．他手臂下夹着一本书。
He was a boy from a poor home. 他是来自穷苦家庭的孩子。
I saw a girl watering the flowers. 我看见一个女孩在浇花。
Anna had a boy friend named James. 安娜有个男朋友名叫詹姆斯。
He arrived half an hour ago. 他是半小时前到达的。
He is an able man. 他是一个能干的人。
Give him an inch and he will take a mile. 他会得寸进尺。
The book is based on an actual case. 这书是根据一个实际案例写的。
He decided to put an advertisement in the newspapers. 他决定在报上登一份广告。
2.任何…都(from www.zkenglish.com)：
A bird has wings. 鸟有翅膀。
A square has four sides. 正方形有四条边。
A dog is an animal. 狗是动物。
3.每(一)：
He comes home once a week. 他每周回一次家。
The doctor told him to bathe his eyes twice a day. 医生让他每天洗两次眼睛。
The ducks were force-fed several times a day. 这种鸭子每天强行喂食好几次。
4.某，某一个(from www.zkenglish.com)：
A Mr. Black just came to see you. 刚才一个叫布莱克先生的人来看你。
The house next door has been bought by a Mr Jones. 隔壁的房子被一个叫琼斯的先生的人买下了。
【考点说明】
1. 用 a 还是用an：一般说来，在辅音或半元音开头的词前用a，而在元音开头的词前用an。注意：有些以元音字母开头的单词，由于第一个音不是元音而是辅音，其前仍用a而不用an(from www.zkenglish.com)。
2. 单数可数名词若泛指，其前需加 a / an，不要从汉语习惯出发，漏掉此不定冠词，如不能说Her father is famous film poet.(应在is加a)
3.不能与指示代词、物主代词、名词所有格等连用，如不说 my a good friend，可改说 a good friend of mine。

生词表: