数词数词分为基数词和序数词.基数词表示人或事物的数量.序数词表示人或事物的次序.1. 基本的基数词和序数词的构成: 基数词序数词 one 1 the first ——青夏教育精英家教网—

数词数词分为基数词和序数词.基数词表示人或事物的数量.序数词表示人或事物的次序.1. 基本的基数词和序数词的构成: 基数词序数词 one 1 the first 1st two 2 the second 2nd three 3 the third 3rd four 4 the fourth 4th five 5 the fifth 5th six 6 the sixth 6th seven 7 the seventh 7th eight 8 the eighth 8th nine 9 the ninth 9th ten 10 the tenth 10th eleven 11 the eleventh 11th twelve 12 the twelfth 12th thirteen 13 the thirteenth 13th fourteen 14 the fourteenth 14th fifteen 15 the fifteenth 15th sixteen 16 the sixteenth 16th seventeen 17 the seventeenth 17th eighteen 18 the eighteenth 18th nineteen 19 the nineteenth 19th twenty 20 the twentieth 20th twenty-one 21 the twenty-first 21st thirty 30 the thirtieth 30th forty 40 the fortieth 40th fifty 50 the fiftieth 50th sixty 60 the sixtieth 60th seventy 70 the seventieth 70th eighty 80 the eightieth 80th ninety 90 the ninetieth 90th a(one) hundred 100 the hundredth 100th a(one) thousand 1000 the thousandth 1000th a(one) million 1 000 000 the millionth 1 000 000th a(one) billion 1 000 000 000 the billionth 1 000 000 000th 1) 基数词的表达法: ① 1-12的基数词是独立的单词. ② 13-19的基数词均以-teen结尾.注意thirteen, fifteen, eighteen的拼写. ③ 20-90的整十位数均以-ty结尾.注意twenty, thirty, forty, fifty的拼写. ④ 几十几的基数词是由十位数词和个位数词合成.中间加连字符“- .例如: 21: twenty-one; 32: thirty-two ⑤ 三位数的构成:几+百+and+末位数.例如: 102: one hundred and two 654: six hundred and fifty-four ⑥ 千以上的数字的读法:从后往前.每三位数一个单位.例如: 3762: three thousand seven hundred and sixty-two 98733: ninety-eight thousand seven hundred thirty-three 高分突破: ① 基数词可以和名词构成合成形容词.但名词要用单数.例如: a 7-year-old girl 一个七岁大的小女孩 ② “几十的数词的复数形式可以表示人的岁数或年代.例如: in his forties 在他四十多岁时 in the 1940s 在二十世纪四十年代 ③ 数词hundred, thousand, million, billion等前无修饰词时.须用复数且后常接介词of.如有many.some.several.a few等修饰词时.可用复数或单数形式.但复数时常有介词of.例如: three hundred kids hundreds of kids many thousand kids = many thousands of kids 2) 序数词的表达法: 序数词＝基数词+th(第1,第2,第3为first, second, third),但要注意: ① fifth, eighth, ninth, twelfth的拼写. ② 以ty结尾的基数词变词尾为tie再加th. ③ 几十几以上的基数词变序数词时只有个位数变为序数词. 2 数词的应用: 1) 表示时钟.例如:seven o’clock, eight fifty 2) 表示编号.例如: Unit One = the first unit Bus 107 = the number 107 bus 3) 表示年月.例如: July 27, 2005 4) 分数的表达法: 分子用基数词.分母用序数词.当分子大于1时.分母用复数.例如: 1/3: one third 4/5: four fifths 高分突破: 1/2: one second = a/one half 1/4: one fourth = a/one quarter 3/4: three fourths = three quarters 5) 倍数的表达法: 两倍用twice.三倍以上用基数词+times表示.常见句型如下: ① ...times + as...as... 例如: This bag of bananas is twice as heavy as that one. ② ...times + 比较级 + than... 例如: My ruler is three times longer than yours. ③ ...times the size(height, length, weight) of ... 例如: This tree is twice the height of that one. [强化训练] 【查看更多】

题目列表(包括答案和解析)

小博士：仔细观察下面的基数词和对应的序数词的区别和变化，你会发现这种变化是有规律的，你能归纳出来吗？请根据规律填出所缺的基数词和序数词，并特别注意黑体字的词。

one	first	eleven	eleventh	twenty-one	twenty-first
two	second	twelve	twelfth	twenty-two	twenty-second
three	third	thirteen	thirteenth	twenty-three	twenty-third
four	fourth	fourteen	fourteenth	twenty-four	______
five	fifth	fifteen	______	twenty-five	twenty-fifth
six	sixth	sixteen	sixteenth	twenty-six	twenty-sixth
seven	______	seventeen	seventeenth	twenty-seven	twenty-seventh
eight	eighth	eighteen	eighteenth	twenty-eight	twenty-eighth
nine	ninth	nineteen	nineteenth	twenty-nine	twenty-ninth
ten	tenth	twenty	twentieth	thirty	thirtieth
thirty-one	thirty-first fortieth ninetieth		hundred	hundredth
forty			thousand	thousandth
ninety			million	millionth