用于某些形容词前,使之名词化,表示 一类人或事物
例如:The rich are not always happier than the poor
The young 年轻人;the old 老年人;the poor 穷人;the injured 受伤的人12
用于复数的姓氏前,表示夫妇二人或全家人
例如:The Greens are at table
The Chens will move to Nanjing
用于江、河、湖、海,山脉与群岛等专有名词前
例如:the Yangtze River the Huanghe River the West Lake the Red Sea the Philippines the Hawaiian Islands14
乐器的名词前
例如:the working class the Communist Youth League play the piano play the violin注意:I bought a piano yesterday
身体的某部位接受外来的动作时,在表示该部位的名词前,必须用定冠词,不可以用物主代词替换
例如:She caught me by the arm
His father hit him on the head
He patted her in the head Punch sb in the noise
用于年的复数形式前,表示年代
例如:in the 1990’s In the 1870’s, Marx was already in his fifties
不定冠词:1
表示“一个”的意思,与数词 one 相同
例如:Rome was not built in a day
罗马不是一天建成的;伟业非一日之功 2
表示一类人或事物
例如:A dog