定冠词：特指 the i want the bike.
冠词
不定冠词: 广泛 a/an I want a book
1.冠词的用法
These cakes are tasty. Would you like a third one?
This is a most useful book for English learners.// a most == very
a: 表示 又一个 非常
A Mr.Green called this morning.
The Greens are sitting at the table. // The + 姓史 表示一家人
// a 一份
Let me buy you a beer/chocolate/sandwich.
Two coffees, please.
2.定冠词用法
I have a dog. The dog is very cute.
The air is free but precious. // earth/moon/sun
// sky/world/universe
// a big/red/sun
形容词 比较级、最高级前面 The poor/rich/old/blind/unkonw/disabled.
He is the taller of the two children.
This is the best lesson i've ever had.
I want the third one. 序数词 the last/same/next/right/wrong.
You're the only one I want.
I can play the guitar, but not the piano.// 乐器
i'm paid by the hour/day/week/month/year
Eggs are sold by the dozen.// 12
季节、月份、星期、节假日、三餐、学科、球类、棋类、疾病、
独特意义的专有名词：人名、地名、街道名
he is dean of our department.// 独一无二
he is a dean of our department.// 有多个系主任