思维导图数词
《思维导图数词》
一、 数词概述
1.1 定义
1.2 分类
- 基数词 (Cardinal Numerals)
- 表示数目的词，如 one, two, three...
- 序数词 (Ordinal Numerals)
- 表示顺序的词，如 first, second, third...
- 分数词 (Fractional Numerals)
- 表示分数的词，如 one-half, two-thirds...
- 倍数词 (Multiplicative Numerals)
- 表示倍数的词，如 once, twice, three times...
- 百分数 (Percentage)
- 表示百分比的词，如 10%, 50%, 100%...
1.3 用法特点
- 可以单独使用，也可以与其他词类构成短语。
- 可以作主语、宾语、表语、定语等。
- 基数词与序数词之间存在转换关系。
- 数词与量词常常搭配使用。
二、 基数词 (Cardinal Numerals)
2.1 基本基数词
- 0: zero / nought / oh (口语)
- 1: one
- 2: two
- 3: three
- 4: four
- 5: five
- 6: six
- 7: seven
- 8: eight
- 9: nine
- 10: ten
- 11: eleven
- 12: twelve
- 13: thirteen
- 14: fourteen
- 15: fifteen
- 16: sixteen
- 17: seventeen
- 18: eighteen
- 19: nineteen
- 20: twenty
- 30: thirty
- 40: forty
- 50: fifty
- 60: sixty
- 70: seventy
- 80: eighty
- 90: ninety
- 100: hundred
- 1,000: thousand
- 1,000,000: million
- 1,000,000,000: billion (美式英语) / milliard (英式英语)
- 1,000,000,000,000: trillion
2.2 基数词的构成
- 21-99: tens + ones (用连字符连接)
- 如: 21 (twenty-one), 35 (thirty-five)
- 101-999: hundreds + and + tens/ones
- 如: 101 (one hundred and one), 256 (two hundred and fifty-six)
- 1,001 以上: thousands/millions/billions + and + hundreds/tens/ones
- 如: 1,234 (one thousand two hundred and thirty-four), 1,000,000 (one million)
2.3 注意事项
- 在英语中，数字每隔三位用逗号分隔（从右向左）。
- 在书写数字时，通常用连字符连接两位数的个位数和十位数。
- “hundred”, “thousand”, “million”, “billion” 等词，在表示确切数字时，一般不加复数。
- 如: two hundred (正确), two hundreds (错误)
- 当表示“成百上千”时，可以加复数。
- 如: hundreds of people (成百上千的人), thousands of stars (成千上万的星星)
- “and” 通常放在百位数和十位数之间。
三、 序数词 (Ordinal Numerals)
3.1 基本序数词
- 1st: first
- 2nd: second
- 3rd: third
- 4th: fourth
- 5th: fifth
- 6th: sixth
- 7th: seventh
- 8th: eighth
- 9th: ninth
- 10th: tenth
- 11th: eleventh
- 12th: twelfth
- 13th: thirteenth
- 14th: fourteenth
- 15th: fifteenth
- 16th: sixteenth
- 17th: seventeenth
- 18th: eighteenth
- 19th: nineteenth
- 20th: twentieth
- 21st: twenty-first
- 22nd: twenty-second
- 23rd: twenty-third
- 30th: thirtieth
- 40th: fortieth
- 50th: fiftieth
- 60th: sixtieth
- 70th: seventieth
- 80th: eightieth
- 90th: ninetieth
- 100th: hundredth
- 1000th: thousandth
3.2 序数词的构成
- 一般情况下，在基数词后加 "-th"。
- 如: four -> fourth, six -> sixth
- 特殊变化：
- one -> first
- two -> second
- three -> third
- five -> fifth
- eight -> eighth
- nine -> ninth
- twelve -> twelfth
- 以 "y" 结尾的词，将 "y" 变为 "ie" 再加 "-th"。
- 如: twenty -> twentieth, forty -> fortieth
3.3 用法
- 表示日期。
- 如: January 1st (一月一日), May 3rd (五月三日)
- 表示顺序。
- 如: the first page (第一页), the second chance (第二次机会)
- 作定语。
- 如: the third person (第三个人)
四、 分数词 (Fractional Numerals)
4.1 构成
- 分子用基数词，分母用序数词。
- 如: 1/2 (one-half), 1/3 (one-third), 1/4 (one-fourth / one-quarter)
- 当分子大于 1 时，分母用复数。
- 如: 2/3 (two-thirds), 3/4 (three-fourths / three-quarters)
4.2 表达方式
- 简单分数: 直接使用分数词。
- 带分数: 整数部分 + and + 分数部分。
- 如: 2 1/2 (two and a half)
五、 倍数词 (Multiplicative Numerals)
5.1 常用表达
- once (一次)
- twice (两次)
- three times (三次)
- four times (四次)
- ...
5.2 用法
- A is twice as big as B (A 是 B 的两倍大)
- A is three times larger than B (A 比 B 大三倍)
- A is twice the size of B (A 是 B 的两倍大小)
六、 百分数 (Percentage)
6.1 表达方式
- number + percent
- 如: 10% (ten percent), 50% (fifty percent), 100% (one hundred percent)
6.2 用法
- The population increased by 10 percent. (人口增长了 10%)
- Only 20 percent of the students passed the exam. (只有 20% 的学生通过了考试)
