不定冠词用法A/an：
a/an与one同源，表示微弱的“一”的概念，但并不强调数目，只表示为不特定者，a用于辅音音素前，an用于元音因素前 a university/a European/a usual thing/an hour/an honest man/an honorable task/an orange/an umbrella
l 表数量“一”：意思和one差不多，但数量概念比one弱。他俩有时可以互换，但在一些习惯用语种不能互换，once upon a time从前/one day有一天/an hour or two一两个小时/one or two hours一两个小时
l 表某一类人或事物： A horse is smaller than an e lephant 马比大象小
l 表泛指的某人某物: A boy is waiting for you
l 表示单位量词的“每一”：时间，速度，价格等意义时表“每一”，正式文体常用each，every代替， We have a music class once a week(每一周)
l 用语集体名词，物质名词，抽象名词，专有名词前：I was in a large class(集体）
l 表某种身份，国籍，职业：I want to be a doctor
l 用语序数词前：I have three books，i want to buy a fourth one
l 习惯用法中（需死记考试常考)：a bit of一点，a moment ago刚才，after a while过了一会儿，once in a while偶尔，take a seat，have a cold/cough/fever/headache感冒/咳嗽/发烧//头痛，have a good time，in a hurry，a little，a lot of，with a smile微笑着，for a time暂时，in a loud voice大声地，make a living谋生，make a mistake犯错误，make a face做鬼脸，make a speech演讲，make a promise许诺，go out for a walk外出散步，take a message for sb为某人捎口信
定冠词用法The：
l 表示人或事物的某一类：The blue whale lives in oceans
l 表特定的人或物：The dictionary on the desk is mine
l 上文中已提到过的人或物：I found a picture in the box.The picture was very beautiful
l 独一无二的事物：Man cannot live without The sun
l 最高级和序数词前：Maths is the most difficult subject and English is the easiest，I think.
l 用于“the+比较级...,the+比较级...”结构:The more careful you are，the fewer mistakes you’ll make.
l 用于名词化的形容词前:The new is sure to replace the old（新事物一定会取代旧事物)
l 表西洋乐器等的名词：play the piano/violin/drum
l 姓氏复数前表全家人：The Smiths史密斯家族
l 集体名词，物质名词，专有名词前：The people in this country are kind(复数概念)/Have you ever been to the Great Wall?(专有名词)/The iron is usually harder than the stone铁比石头硬(普通名词变专有名词要加the)
l 习惯用法中: all the time一直，at the foot of在...脚下，make the bed铺床，by the way顺便问一下，on the whole总之，in the past在过去，at the same time同时，in the morning在上午，the day before yesterday前天，in the day在白天，in the sky在空中，in the world在世界上，in/on the street在街上，in the middle of在..中间，on the way to在去...路上，all the same完全一样，with the help of在...的帮助下，go to the cinema去看电影
不用冠词的情况：
l 物质名词表泛指，抽象名词表概念，专有名词表人名/地名/国名/城市/街道和词首为Mount的山及大多数湖泊时：Money is not everything；Wood is used to make paper木头被用来造纸；/Music can bring people pleasure
l 泛指的可数名词复数前：Trees can help clean the air
l 季节，月份，星期，节日：Spring is the best season
l 三餐，球类运动不需要: Have breakfast/play football/basketball
l 学科，语言名词前：English is one of the most important language
l 独一无二的职位，头衔，称呼：Doctor，I’m not feeling myself well today
l 名词前有某些限定词：Bill's camera is like mine
l 一人身兼多个身份(只在第一个名词前加,其他名词不加冠词)：a teacher and writer一位老师兼作家
l 连系动词turn后的名词前：I hope to turn a famous pianist，but I turned teacher我希望能变成一个著名的钢琴家，但最后变成了老师(turn后名词前有形容词修饰要加冠词，如每一则不需要加冠词)
l 习惯用法中：at night在晚上，at work在上班，at home在家，in danger在危险中，go to school上学，go to the school去学校，lose weight减肥，ask for advice，keep in touch with，in fact事实上，at dinner在吃饭，in trouble处于困境，after school放学后，on fire着火，by hand手工，by
bus/car/taxi/water/plane/train乘坐公交/汽车/出租车/船/飞机/火车，watch TV看电视，come back to life苏醒，have sports进行运动，pay attention to注意，take care of照顾，take part in参加
l 用法比较：at table在吃饭/at the table在桌子旁 at school上学/at the school在学校/by day白天/by the day按日计算/in future今后/in the future将来/in prison坐牢/in the prison在监狱里
冠词的位置：
用与名词前，一般位于一个名词或名词短语的最前面
用语as/so...结构中，一般在as/so修饰的形容词后：i have never spent as delightful a time as this Sunday
用语such....结构中，a/an在such之后，形容词前：The teacher asked such a hard question that none of us could answer it
用于too...to结构中，a/an在too修饰的形容词后：Mary is too young a girl to be left by herself alone
用于感叹句中：what an interesting book it is！/how timely a rain we've got in such a dry season
名词前有all，both等词时：All the movie theaters are good.