【序数词英语表格（序数词1到100及基数词转序数词）】在英语中，序数词用于表示顺序或排列位置，如“第一”、“第二”等。与基数词不同，序数词通常以“-th”结尾，但也有例外情况。掌握常见的序数词有助于提高英语表达的准确性。以下是对1到100的常见序数词进行整理，并提供从基数词转换为序数词的方法。
一、序数词基本规则
1. 一般情况下：将基数词的末尾字母“y”改为“i”，然后加上“-eth”。
- 例如：twenty → twentieth
- 但注意：four → fourth，five → fifth，nine → ninth 等有特殊变化。
2. 以“-e”结尾的基数词：直接加“-th”。
- 例如：three → third，eight → eighth。
3. 以“-t”结尾的基数词：加“-h”。
- 例如：eight → eighth（但这是特例），twelve → twelfth。
4. 以“-o”结尾的基数词：加“-th”。
- 例如：seven → seventh，ten → tenth。
5. 数字1、2、3：有特殊形式。
- 1 → first
- 2 → second
- 3 → third
二、1到100的序数词表
| 基数词 | 序数词 | 基数词 | 序数词 | 基数词 | 序数词 |
| 1 | first | 31 | thirty-first | 61 | sixty-first |
| 2 | second | 32 | thirty-second | 62 | sixty-second |
| 3 | third | 33 | thirty-third | 63 | sixty-third |
| 4 | fourth | 34 | thirty-fourth | 64 | sixty-fourth |
| 5 | fifth | 35 | thirty-fifth | 65 | sixty-fifth |
| 6 | sixth | 36 | thirty-sixth | 66 | sixty-sixth |
| 7 | seventh | 37 | thirty-seventh | 67 | sixty-seventh |
| 8 | eighth | 38 | thirty-eighth | 68 | sixty-eighth |
| 9 | ninth | 39 | thirty-ninth | 69 | sixty-ninth |
| 10 | tenth | 40 | fortieth | 70 | seventieth |
| 11 | eleventh | 41 | forty-first | 71 | seventy-first |
| 12 | twelfth | 42 | forty-second | 72 | seventy-second |
| 13 | thirteenth | 43 | forty-third | 73 | seventy-third |
| 14 | fourteenth | 44 | forty-fourth | 74 | seventy-fourth |
| 15 | fifteenth | 45 | forty-fifth | 75 | seventy-fifth |
| 16 | sixteenth | 46 | forty-sixth | 76 | seventy-sixth |
| 17 | seventeenth | 47 | forty-seventh | 77 | seventy-seventh |
| 18 | eighteenth | 48 | forty-eighth | 78 | seventy-eighth |
| 19 | nineteenth | 49 | forty-ninth | 79 | seventy-ninth |
| 20 | twentieth | 50 | fiftieth | 80 | eightieth |
| 21 | twenty-first | 51 | fifty-first | 81 | eighty-first |
| 22 | twenty-second | 52 | fifty-second | 82 | eighty-second |
| 23 | twenty-third | 53 | fifty-third | 83 | eighty-third |
| 24 | twenty-fourth | 54 | fifty-fourth | 84 | eighty-fourth |
| 25 | twenty-fifth | 55 | fifty-fifth | 85 | eighty-fifth |
| 26 | twenty-sixth | 56 | fifty-sixth | 86 | eighty-sixth |
| 27 | twenty-seventh | 57 | fifty-seventh | 87 | eighty-seventh |
| 28 | twenty-eighth | 58 | fifty-eighth | 88 | eighty-eighth |
| 29 | twenty-ninth | 59 | fifty-ninth | 89 | eighty-ninth |
| 30 | thirtieth | 60 | sixtieth | 90 | ninetieth |
| 31 | thirty-first | 61 | sixty-first | 91 | ninety-first |
| 32 | thirty-second | 62 | sixty-second | 92 | ninety-second |
| 33 | thirty-third | 63 | sixty-third | 93 | ninety-third |
| 34 | thirty-fourth | 64 | sixty-fourth | 94 | ninety-fourth |
| 35 | thirty-fifth | 65 | sixty-fifth | 95 | ninety-fifth |
| 36 | thirty-sixth | 66 | sixty-sixth | 96 | ninety-sixth |
| 37 | thirty-seventh | 67 | sixty-seventh | 97 | ninety-seventh |
| 38 | thirty-eighth | 68 | sixty-eighth | 98 | ninety-eighth |
| 39 | thirty-ninth | 69 | sixty-ninth | 99 | ninety-ninth |
| 40 | fortieth | 70 | seventieth | 100 | one hundredth |
三、总结
序数词在日常英语中使用广泛，尤其是在描述日期、排名、比赛名次等场合。虽然大多数序数词遵循一定的构词规则，但仍有部分需要特别记忆，如“first”、“second”、“third”等。通过理解这些规则和规律，可以更轻松地掌握和使用序数词。对于较大的数字，如“100”以上，也可以按照类似方式构造，例如“101”是“one hundred and first”，“110”是“one hundred and tenth”。
掌握序数词不仅有助于提高语言准确性，也能增强表达的清晰度和专业性。建议多加练习，结合实际语境进行应用。
