1.單數可數名詞若泛指,其前需加 a/an,不要從漢語習慣出發,漏掉此不定冠詞:
例:
伯林頓拱廊是倫敦著名的購物場所。
正確
Burlington Arcade is a famous shopping place in London.
錯誤
Burlington Arcade is famous shopping place in London.
2.專有名詞轉化為普通名詞,其前可用 a(an),表示某某人或某某人的一部作品、藝術品等:
正確
There is a Mr Jones to see you, sir.
先生,有一位叫瓊斯的先生要見你。
Let’s suppose a Mr. So-and-so registers at the hotel.
咱們打個比方吧,有個某某先生來旅館登記。
When he bought the picture he was told it was a Rubens, but he later found out it was a forgery.
有人告訴他那是魯賓斯的畫,但後來他發現那是贗品。
3.物質名詞轉化為普通名詞,其前可以使用 a(an),有時表示相應產品或種類,有時表示數量關係:
正確
She knows a good wine when she tastes it.
她只要一嘗就能分辨酒的好壞。
I had a coffee and she had a chocolate.
我喝了一杯咖啡,而她喝了一杯可可。
4.在序數詞之前使用 a(an),可以表示數量或序數的增加:
正確
Soon I saw a second plane.
不久我又看到了一架飛機。
A:This is the second time that I』ve read the book.
B:Do you want to read it a third time?
A:這是我第二次看這本書。
B:你還想看第三次嗎?
5.與形容詞的最高級連用,表示「非常」「很」等:
正確
They have embarked on a most interesting new plan.
他們己經著手作一個非常有趣的新計劃。
He thanked his host for a most enjoyable party.
他感謝主人請他參加一個非常愉快的聚會。
Gascoigne had received an offer of help from a most unlikely source.
賈斯昆從一個最不可能的來源得到了幫助。
6.用於修飾名詞的定語前,表示某種狀態。此時的不定冠詞含有類似 a kind of 的意思:
正確
The island has a mild climate.
那個島氣候溫和。
I have a good breakfast and good meal in the evening, and never trouble with lunch.
我早餐吃得很好,晚上也吃得很好,午餐也從不麻煩。
He lives in a world of fantasy.
他生活在幻想的世界裡。
7.不定冠詞 a(an)與數詞 one 都可表示「一」,但是兩者有差別:不定冠詞 a(an)表示「類別」概念,而數詞 one 表示「數量」概念:
正確
She has a new baby: it was born last week.
她有一個上周才出生的嬰兒。
She has a woman who cleans for her twice a week.
她有一個女幫工,每星期幫她打掃兩次。
8.兩個單數可數名詞連用表示一個整體時,只用一個冠詞:
正確
He is a teacher and poet.
他既是老師又是詩人。
There’s a horse and cart on the road.
路上有一輛馬車。
9.與副詞 quite/rather 連用時,a(an)一般要後置,但若其後的名詞前有形容詞修飾,則 a(an)放在 quite/rather 之前或之後均可以:
正確
He is rather a fool.
他是個大傻瓜。
It is quite a good book.
那是本很好的書。
It is a quite good book.
那是本很好的書
錯誤
He is a rather fool.
(因為名詞前無形容詞,所以錯誤)