The indefinite articles A/AN are used when talking about a general or non-specific noun.不定冠词A/AN指的是一般名词或非特定名词。Where is a teacher?/A book is on the table./Did you bring a cake?老师在哪里？/桌子上有一本书。/你带蛋糕了吗？

But unlike the definite article, A/AN can only be used with singular countable nouns. We can’t say a teachers, a books, a cakes.但与定冠词不同，A/AN只能用于单数可数名词。我们不能说是a teachers, a books, a cakes。Instead we use the definite article: the teachers, the books, the cakes.取而代之的是定冠词：the teachers, the books, the cakes。Where are the teachers?/The books are on the table./Did you bring the cakes?老师们在哪里？/书在桌子上。/你把蛋糕带来了吗？Remember!记得！In English, we use an with any noun that starts with a vowel sound, NOT with a noun that starts with a vowel. This is very important because many nouns that start with a vowel don’t have a vowel sound such as university, we say a university NOT an university. Also, many vowel sounding words don’t start with a vowel for example hour, we say an hour.在英语中，我们使用以元音开头的任何名词，而不是以元音开头的名词。这一点非常重要，因为许多以元音开头的名词没有元音，比如大学，我们说的大学不是大学。而且，许多听起来像元音的单词都不是以元音开头的，比如小时，我们说一小时。Below is a list of nouns you can use ‘an’ with:下面是可以与“an”一起使用的名词列表：an oven/an apple/an honour/an octopus/an auntie/an injury/an umbrella/an egg烤箱/苹果/荣誉/章鱼/阿姨/受伤/雨伞/鸡蛋Here is a list of nouns used with A:下面是与a一起使用的名词列表：a table/a pillow/a university/a cake/a bed/a utopia桌子/枕头/大学/蛋糕/床/乌托邦Here is a list of nouns used with An:下面是与一个An连用的名词列表：an oven/an orange/an honour/an invention/an hour/an evening烤箱/桔子/荣誉/发明/一小时/一晚Here are examples of how we use A and An in a sentence:下面是我们如何在句子中使用A和An的例子：There is a university close to here./The movie starts in an hour./There is an octopus in the water./The new house doesn’t have an oven but it has a washing machine./I need an umbrella, it’s raining outside.附近有一所大学。/电影一小时后开始。/水里有一只章鱼。/新房子没有烤箱，但有洗衣机。/我需要一把伞，外面在下雨。THE is called a definite article, we use the with all nouns and for specific nouns, like a certain person or a particular thing.The被称为定冠词，我们使用与所有名词和特定名词，如某个人或某事物。For example:举例：Where is the teacher?/The book is on the table/Did you bring the cake?老师在哪里？/书在桌子上/你带蛋糕了吗？The examples above are talking about specific things or people. In the first example, they are looking for a specific teacher, maybe a biology teacher or an English teacher. They are not looking for any teacher, they want to know where that particular teacher is.上面的例子是谈论特定的事物或人。在第一个例子中，他们正在寻找一个特定的老师，也许是一个生物老师或者一个英语老师。他们不找老师，他们想知道那个老师在哪里。The other two examples have a similar concept, example two is talking about a specific book on a specific table. And the third example is talking about a particular cake, maybe a birthday cake or a wedding cake.另外两个例子有一个相似的概念，例子二是在一个特定的桌子上谈论一本特定的书。第三个例子是一个特别的蛋糕，可能是生日蛋糕或者婚礼蛋糕。