词法｜07 数词

7.1 基数词

基数词的表达方法

1. 在英语中表示数目的词称为基数词

1	one
2	two			20	twenty
3	three	13	thirteen	30	thirty	23	twenty-three
4	four	14	fourteen	40	forty
5	five	15	fifteen	50	fifty	35	thirty-five
6	six	16	sixteen	60	sixty
7	seven	17	seventeen	70	seventy
8	eight	18	eighteen	80	eighty
9	nine	19	nineteen	90	ninety
10	ten			100	one(a) hundred
11	eveven					101	one hundred and one
12	twelve

1. 21-99先说“几十”，再说“几”，中间加连字符；
   • 23—twenty-three.
   • 89—eighty-nine.
2. 101-999先说“几百”，再加and，再加末两位数或末位数；
   • 586—five hundred and eighty-six
   • 803—eight hundred and three
3. 1000以上，先从右往左数，每三位数加一个“，”，第一个“，”前为thousand，第二个“，”前为million，第三个“，”前为billion，然后一节一节地逐一表示。
   • 1,001—one thousand and one
   • 6,260,309—six million two hundred and sixty thousand three hundred and nine

基数词的用法

1. 作主语
   • Four of them come from Paris.
2. 作宾语
   • —How many books would you like.
   • —I would like two.
3. 作表语
   • Seven minus two is five.
4. 作定语
   • There are three people in my family.
5. 作同位语
   • You two will go swimming with us.
6. 表示时刻
   • I watch CCTV News at seven o’clock every evening.
7. 表不确定的数字时，数词用复数。若带名词，再加of。
   • hundreds of (数百，成百上千的)
   • thousands of (数千，成千上万的)
   • millions of （数百万）
   • They arrived in twos and threes.
8. 表示“…十”的数词的复数可以表示人的岁数或年代
   • He is in his early thieties.
   • This took place in the 1930s.
9. 表达小数
   • 5.8—five point eight
   • 0.13—zero point three

7.2 序数词

序数词的表达方法

1. 在英语中表示顺序、次序的词称为序数词。

				21st	twenty-first
		20th	twentieth	22nd	twenty-second
13th	thirteenth	30th	thirtieth	23rd	twenty-third
14th	fourteentth	40th	fortieth
15th	fifteenth	50th	fiftieth	35th	thirty-fifth
16th	sixteenth	60th	sixtieth
17th	seventeenth	70th	seventieth
18th	eighteenth	80th	eightieth
19th	nineteenth	90th	ninetieth
		100th	one hundredth
				101st	one hundred and first

1. 一般在基数词后加th
   • four—fourth.
   • thirteen—thirteenth.
2. 不规则变化；
   • one — first
   • two — second
   • three — third
   • five — fifth
   • eight — eighth
   • nine — ninth
   • twelve — twelfth
3. 以y结尾的十位整数，变y为ie再加th。
   • twenty — twentieth
   • forty — fortieth
   • ninety — ninetieth
4. 从二十一后的“几十几”直到“几百几十几”或“几千几百几十几”只将个位的基数词变为序数词。
   • twenty-first
   • two hundred and forty-fifth

序数词的用法

1. 序数词作定语时，一般要与定冠词或物主代词连用
   • Tom is their second son.
   • He is the first one to come here.
2. 序数词有时可与不定冠词连用，表示数量上”又一“，“再一”
   • He tried a second time.
   • Shall I ask him a third time?
3. 序数词的缩写形式为：阿拉伯数字加上这个词的末尾两个字母。
   • 1st，2nd，3rd，4th，20th，21st，22nd，23rd.
4. 表示年、月、日时，年用基数词，日用序数词。
   • 2005年8月15日：
     • 【英】15,8,2005 = 15th, August, 2005;
     • 【美】8,15,2005 = August 15th, 2005.
5. 基数词和序数词都可以用来给数字编号。
   • No.1 (1号)
   • No.3 bus 3路公共汽车
   • Room 103 103号房间
   • The first lesson = Lesson Two (第二课)
6. 分数的表达：分子用基数词，分母用序数词，分子大于1时，分母加s
   • 1/3 one third
   • 2/5 two fifths
7. 数学运算的表达
   • 3+5=8 — Three plus/and five is eight.
   • 9-2=7 — Nine minus two is seven.
   • 6×5=30 — Five times six is thirty.
   • 8/2=4 — Eight divided by two is four.