1、如:eighty-five 85twenty-six 26(2)三位数的基数词须在百位和十位(若无十位则和个位)之间用and连接。three hundred and sixty-five 365two hundred and six 206(3)基数词的复数形式。当基数词hundred,thousand,million,billion等词前有具体数词或several修饰时,必须用单数。several hundred years ago几百年前two thousand students两千个学生2. 基数词的特殊用法:(1)表示“几十年代”或“几十岁”时,用逢十的基数词的复数形式。in the
2、1990s 20世纪90年代in ones twenties在某人20多岁时(2)用在习语中。in twos and threes三三两两地二、序数词序数词应注意的几点事项:1. 多位数的基数词变成序数词时,只需将末位基数词变成序数词,前边的基数词不变。forty-two 42 forty-second第42nine-hundred 900 nine-hundredth第9002. 当序数词用阿拉伯数字表示时,必须在数字后加上序数词的最后两个字母。21st第2132nd第323. 序数词前一般要用定冠词the,如果序数词前用a或an时,则表示“又一;再一”(没有具体范围的限制)。Though
3、he had failed twice,he wanted to try a third time.尽管他已失败了两次,他还想再试一次。The little monkey had had three apples,and he wanted to eat a fourth one.那只小猴子已经吃了3个苹果,他还想再吃一个。三、分数和百分数1. 分数(1)分数的分子用基数词,分母用序数词。one fifth五分之一one tenth十分之一(2)当分子大于1时,分母用序数词的复数。two thirds三分之二five eighths八分之五(3)当分子是1时,可以用one也可以用a.如:a s
4、econd = one seconda third = one third(4)当分母是2和4时,分别可以用half和quarter代替。a half二分之一three quarters四分之三2. 百分数百分数用percent表示。forty percent百分之四十three percent百分之三3. 分数、百分数与主谓一致分数、百分数的考查往往和主谓一致相联系。当分数、百分数修饰可数名词的复数时,谓语动词用复数形式;当分数、百分数修饰不可数名词时,谓语动词用单数形式。Eighty percent of the students in our school come from Henan
5、.我们学校百分之八十的学生来自河南。Three fourths of the students in my class are interested in English.我们班四分之三的学生对英语感兴趣。Two thirds of the water on the earth is sea water.地球上三分之二的水是海水。四、倍数的表示法1. 表示“几倍大小(长短;数量)”,由“倍数+ the size(length,amount)”结构组成。The earth is forth-nine times the size of the moon.2. 表示“比大几倍”,由“倍数+形容词(副词)比较级+ than +被比较部分”结构组成。This box is three times bigger than that one.3. 表示“是倍”,由“倍数+ as +形容词+ as +被比较部分”结构组成。Our factory is twice as big as theirs.