. 特指某（些）人或某（些）事物. Give me the book. Did you hear the talk given by Mr Li? How do you like the film. Have you got the letter? 2. 指談話雙方都知道的人或事物. Where is the teacher? Open the door. 3. 復(fù)述上文提過的人或事物. I have a beautiful wallet, but the wallet was stolen yesterday. 4. 世界上獨(dú)一無二的事物等（月亮、地球、天空、宇宙） The sun rises in the east. The earth goes round the sun. the globe, the universe. the atmosphere大氣層 5. 用在方位名詞前 in the south, in the west ,in the north 6. 用在序數(shù)詞或形容詞最高級(jí)前 The first thing I want to say is to listen carefully in class. He is the tallest one in our class. 7、表示兩者間“較……的一個(gè)”時(shí)用定冠詞 The older of the two noblemen took a light. He is the taller of the two boys. 8. 用在單數(shù)可數(shù)名詞前表示一類人或事物. The horse is a useful animal. 9. 定冠詞用在形容詞前,表示一類人或東西. The rich, the poor ,the wounded ,the deaf 10. 冠詞可用在黨派、階級(jí)、民族名詞前 The Chinese people中華民族 The working class 工人階級(jí) The Communist Party 11、用在姓氏的復(fù)數(shù)形式前表示一家人,或這一姓的夫婦二人. The Lius live upstairs. The Johns are watching TV. 12、在樂器前加the the piano the violin 13、在習(xí)慣性短語中 in the morning in the afternoon 14、在人或物后有限定性的后置定語 The man standing by the gate is Li Feng. 15、代替所有格代詞,表示人體的一部分 He received a blow on the head 他頭上挨了一擊. John’s brother took him by the hand. 約翰的哥哥牽著他的手. 16、在世紀(jì),年代名詞前用冠詞. In the 1980s或in the 1980’s 20世紀(jì)80年代 in the nineteenth century 二十世紀(jì)