数词的用法,一、数词的种类,1、基数词：表示数量多少的词。,2、序数词：表示顺序的词。一般在基数词后加th。,特殊形式的序数词：,onefirst twosecond threethird fivefifth eighteighth nineninth twelvetwelfth,表示“几十”的序数词，将基数词末尾的y改为i，再加eth。,twentytwentiethninetyninetieth,fifty-twoeighty-seven,fifty-second,eighty-seventh,基数词在句中可作主语、宾语、定语、表语、同位语。,二、数词的句法功能,1、基数词的句法功能,The two happily opened the box.I need three altogether.Four students are playing volleyball outside. We are sixteen. They three tried to finish the task before sunset.,主语,宾语,定语,表语,同位语,2、序数词的句法功能,序数词在句中可作主语、宾语、定语、表语。,The second is what I really need. He choose the second. We are to carry out the first plan. She is the second in our class.,主语,宾语,定语,表语,分子用基数词，分母用序数词；分子大于1，分母要用复数形式。,三、分数表达法,1/3,one third, a third,3/4,three fourths, three quarters,3 1/4,three and one fourth,1/2,1/4,a half,a quarter,四、小数、百分数的读法,8848.18米,0.002,50,89.99,小数点读作point；%读作percent,eight thousand, eight hundred and forty-eight point one eight meters,zero point zero zero two,fifty percent,eighty-nine point nine nine percent,五、数词的考点归纳,1、表示人的不确切岁数或年代，用in ones thirties或者in the 1990s表示。,他三十多岁时成为了教授。,He became a professor in his thirties.,这个故事发生在二十世纪六十年代。,The story happened in the 1960s.,2、当hundred, thousand, million, billion, dozen（打，十二）, score（二十）等词前面有具体的数词时，它们不能用复数，也不与of连用。如果前面没有具体的数词，需加“s”，并与of连用。,大厅里有三百人。,There are three hundred people in the hall.,每年数百万人死于癌症。,Millions of people die of cancer every year.,3、基数词与复数名词用连字符号连接作定语时，名词用单数形式。,昨晚他写了一篇800字的作文。,He wrote an 800-word composition last night.,李平在100米比赛中获得了第一名。,Li Ping won the first prize in the 100-meter race.,4、序数词前通常加the或形容词性物主代词或名词所有格；序数词与不定冠词a或an连用时，则表示“再一”，“又一”。,这是我第二次去北京。,Its my first time that I have been to Beijing.,他又失败了，但是他还想再试一次。,He failed again, but he wanted to have a second try.,5、分数、百分数作主语时，谓语动词的单复数取决于它们后面的名词。如果名词是复数形式，动词用复数；反之亦然。,三分之二的大米变质了。,Two thirds of the rice has gone bad.,我们学校70的老师是女性。,70 of the teachers in our school are women.,注意：population（人口，不可数名词）前有分数、百分数修饰时，谓语动词用复数形式。,中国70%的人口生活在农村。,70% of Chinas population live in the countryside.,6、倍数表达法：,（1）主语谓语倍数比较级than,这个房间比那个房间大2倍。,This room is twice bigger than that one.,我比他大10岁。,I am ten years older than he.,（2）主语谓语倍数asas,这家工厂今年生产的机器是去年的5倍。,The machines produced by the factory this year are 5 times as many as those of last year.,（3）主语谓语倍数the名词（length, width, height, size）of,这条河是比那条河长2倍。,This river is twice the length of that one.,