初中英语数词讲解
数词就是表示事物的数量和顺序的词,分基数词和序数词两种。
1.基数词
表示数量多少的词是基数词,如:one, two, three等。构成方法如下:
1)从1-12分别由从one到twelve12个各不相同的词表示。
2)从13-19均以后缀-teen结尾。
3)从20-90的整十数词均以后缀-ty结尾。表示“几十几”时,个位和十位之间需加连字符,如twenty-one, thirty-two, forty-three等。
4)数字的写法和读法:
⑴十位与个位之间要加连字符“-”;
⑵百位和十位之间要加and;
⑶三位数以上的数,从个位往前数,每三位数加一个逗号“,”,从后往前数的第一个逗
号代表thousand,第二个逗号代表million,第三个逗号是billion,注意这几个词不能用复
数形式,后也不能加and。
5)表示具体、准确的数目时,hundred, thousand, million等数词后不能加-s, 如five hundred, six thousand, seven million等。
6)当hundred, thousand等数词与of连用,表示不具体、不准确的数目时,词尾须加-s。如:
thousands of students, millions of trees.
6)当hundred, thousand等数词与of连用,表示不具体、不准确的数目时,词尾须加-s。如:
thousands of students, millions of trees.
2. 序数词
1)不规则变化
2)以-ty结尾的表示“几十”的基数词,先把y变为i,再加-eth
3)表示“第几十几”时,十位数的“几十”仍用基数词,只把个位部分变成序数词就行了。
4)除上述情况外,均在词尾加-th,如ten tenth one hundred one hundredth
三. 数词的用法
(一)表示事物的编号
基数词放到名词的后边,该名词一般要大写;序数词放到名词的前面,加定冠词。
第一课 Lesson 1/ the first lesson. Row 3/ the third row
(二)年、日、时刻表达方法。
“年”用基数词,“日”用序数词,前要加定冠词。读的顺序是月日年。如:1999年5月2日读作:May the second, nineteen ninety。
“时刻”用基数词表达,同时要注意以下两点。
1.表示“整点”时,在基数词后加o’clock;
9:00 o’clock.
2.分钟小于或等于30分钟的,用“分钟数+past+钟点数”形式;分钟数大于30分钟的,用“到下一个钟点所差的分钟数+to+下一个钟点数”形式,也可以依次读钟点数和分钟数。
7:20 twenty past seven或seven twenty.
3.注意两个特殊的表示时间的单位词:30分钟用half,15分钟用a quarter,如:
6:30 读作:half past six
5:45 读作:a quarter to six
6:15 读作:a quarter past six
(3)分数的表达方法
表示分数时,分子用基数,分母用序数,分子大于1,分母用复数。分数修饰名词时,后用of短语。如:
1/3 one third of teachers 3/7 three sevenths of the boys
1/2, 1/4分别用 a half和a quarter表示。
(4)“基数词-名词-形容词”结构
“基数词-名词-形容词”只能用来放到名词前作定语。如:
She is a 3-year-old girl.
They live in a 7-storey-high building.
注:这种结构中名词不能用复数,同时只能作定语。用作表语时,不用连字符,名词有复数。如:
Tony is 10 years old this year.
Tony is a 10-year-old boy.
1.基数词和序数词
Dick, it is the ________ time in ________ days that you’ve made the same mistake.
A. two, three B. second , three C. two, third D. second, third (2007乌鲁木齐)
[解题技巧]
以此立意的试题要求考生能正确使用基数词和序数词:基数词用来表达事物的量;序数词用来表达事物的顺序。
本题的第一空表示顺序用序数词second;第二空用基数词three,答案为B。
2.分数
It is said that the gravity(引力) on Mars is only about __________ of the gravity on earth.
A. three-eighths B. third-eighth C. three-eights D. third-eight(2006苏州)
[解题技巧]
以此立意的试题考查考生能否正确使用分数:分子在前用基数,分母在后用序数。分子大于一,分母用复数,分子与分母之间可以用连字符连起来也可以不用连字符,如two thirds或
two-thirds;当分数修饰名词作定语时,后要跟of,如:two thirds of students 三分之二的学生
本题的选项中只有A项正确。
3.hundred,thousand,million,billion等单位数词
-How many people will come to Beijing next year?
-It’s hard to say, ________ people, I think.
A. million of B. millions of C. three millions D. three millions of (2007芜湖)
[解题技巧]
以此立意的试题考查考生能否正确使用hundred等单位数词。表示单位的数词用法分两种情况:1)当放在具体的数字后边,表示具体的“百、千、百万、十亿”时,不能用复数形式,可以直接修饰名词复数,如two thousand students;2)当表示大概的“几百、几千、几百万、几十亿”时,用“复数形式+of”结构,前边不能用具体的数字,如:thousands of student
s。
本题中只有B项正确。
课堂过手练习
( )1.If you go out at night, you’ll be able to see ____ starts.
A. thousands of B. thousand of
C. nine thousands of D. thousands
( )2.Monday is ___ day of the week.
A. first B. the first
C. the second D. second
( )3.You’ve done it twice. Why not try ____ time?
A. third B. the third C. a third D. once
( )4.Which is the____ month? It’s September.
A. nine B. nineth C. ninth D. ninety
( )5.December is ___ of the year.
A. the twelfth months B. the twelfth month
C. the twelveth months D. twelve months
( )6.There are ___ floors in the building and he lives on the ____ floor.
九大写 A. eighteen, fifteen B. eighteenth, fifteenth
C. eighteen, fiveteen D. eighteen, fifteenth
( )7.I was born ___, 1982.
A. on June 2rd B. in June 2nd
C. on June two D. on June 2
( )8.It’s ____ from our home to the zoo.
A. two and a half hours’ walk
B. a half and two hours walk
C. two hours and a half hour’s walk
D. two and a half hour’s walk
( )9.What time is it now? It’s ___ to six.
A. quarter B. a quarter C. quarto C. a quarto
( )10.Will you be back in ____ ?
A. one or two minutes B. one minute or two
C. two minutes or one D. two or one minute
( )11.Mary’s uncle went to France ____.
A. in his thirties B. on his thirties
C. at his thirties D. about his thirties
( )12.The headmaster wrote a ___ report.
A. two thousand words B.two-thousand-words
C. two-thousand words D. two-thousand-word
( )13.____of the apples in the fruit bowl are soft and sweet.
A. Two-third B. Second-third
C. Two-thirds D. Second-thirds
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