Question

one和a和an的区别是什么，求专业

Answer 1

1. 辅音音素开头的名词或名词短语前用a，注意某些名词是元音字母开头但是首发辅音，还是加a

   例：a university, a European, a one-parent family

2. 元音音素开头的名词前加an，不发音的h打头的单词前也加an

   例：an orange, an Italian, an umbrella, an hour, an hornour

3. 如果缩写单词是按字母的方式读出来，并且以A,E,F,H,I,L,M,N,O,R,S或X开头，前面加an

   例：an MP, an FBI agent, an IOU

4. 如果缩写单词以一个完整的单词形式出现，前面加a或an

   例：a NATO general, a FIFA official, an OPEC meeting

5. 特例：a history (book)，an （或 a）historical (novel)

6. a/an用来形容一个非特指的人、物或事件

   例：I really need a cup of coffee.

   You never see a police officer in this part of town, do you?

7. 数字或数量中用a或an

   例：three times a year, half an hour, a quarter of an hour, a day or so, 50 cents a litre, a week or two, a few, a little, a huge number of ...

8. 所属权一般用a而不是one

   例：She's a colleague of mine.

   That's a friend of Gabriel's.

9. 单数可数名词前加a/an或one都是表示数量为1

   例：We'll be in Australia for one year. （或...a year.）

   Wait here for one minute, and I'll be with you. （或...a minute...）

10. one比a/an更强调时间的长短或数量的大小等

    例：He weighs one hundred and twenty kilos! Would you believe it!

11. 强调谈论的对象是1样东西或1个人，突出数量为1时，用one而不是a/an

    例：Do you want one sandwich or two?

    Are you staying only one night?

    I just took one look at her and she started crying.

12. 固定组合one...other/another中用one而不是a/an

    例：Close one eye, and then the other.

    Bees carry pollen from one plant to another. 

13. 固定词组one day, one evening, one spring等表示某个特定的，但是不明确的日子、夜晚、春天等

    例：Hope to see you again one day.

    One evening, while he was working late at the office...

Answer 2

one只表示“一”的概念，a/an除了表示一以外，还有其他的用法。
1）用于泛指人或事物
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。
A teacher likes putting a watch on his / her desk while lecturing .老师讲课时总爱将手表放在讲台上。
（2) 用于某些词组中。这种用法是约定束成的，我们只有遵从，没有别的选择。例如：
have a rest（休息） have a look（瞧瞧） have a good time（过得开心）
take a shower（淋浴） take a break（休息） take a bath（洗澡）
have a cold（患感冒） get a fever（发烧） develop into a habit （养成习惯）
make a living（谋生） make a guess at（猜测） make a difference between（区分）
in a moment（过一会儿） in a sense（在某种意义上） in a way（在某种程度上）
once in a while（间或） have an advantage over（优于）
have an edge（略胜过）as a result（因此）as a rule（通常）as a whole（总体上说）
（3）在名称或唯一地名前禁用：
例：Mr.Green lives in Bridge Stree.

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一个苹果怎末说

追答

an apple，one apple。都可以。强调数量一个，用后者。

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谢了