# 基数詞
1. 0～100
0 zero, naught / 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 / 21 twenty-one / 22 twenty-two / 23 twenty-three / 24 twenty-four / 25 twenty-five / 26 twenty-six / 27 twenty-seven / 28 twenty-eight / 29 twenty-nine / 30 thirty / 31 thirty-one / 32 thirty-two ….. / 40 forty / 41 forty-one ….. / 50 fifty / 51 fifty-one ….. / 60 sixty / 61 sixty-one ….. / 70 seventy / 71 seventy-one ….. / 80 eighty / 81 eighty-one ….. / 90 ninety / 91 ninety-one ….. / one hundred 100

2. 101～1000
101 one hundred (and) one… / 110 one hundred (and) ten… / 121 one hundred (and) twenty-one… / 200 two hundred… / 278 two hundred (and) seventy-eight… / 300 three hundred… / 400 four hundred… / 500 five hundred… / 600 six hundred… / 700 seven hundred… / 800 eight hundred…
/ 900 nine hundred… / 999 nine hundred (and) ninety-nine / 1000 one housand

# 序数詞 (第1の, 第2の, 第～の/ 一番目, 二番目, ～番目/ ～日)
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 / 24th: twenty-fourth … / 30th: thirtieth …. / 40th: fortieth … / 50th: fiftieth … / 60th: sixtieth … / 70th: seventieth … / 80th: eightieth … / 90th: ninetieth … / 99th: ninety-ninth / 100th: hundredth …

1. 通常、基数詞に -th をつけて序数詞にする
*7 (seven) → 7th (seventh)

2. 語尾が -ve で終わる数は ve を f に変え -th をつける
*5 (five) → 5th (fifth)

3. 語尾が -t で終わる数は -h だけをつける
*8 (eight) → 8th (eighth)

4. 語尾が -y で終わる数は y を -ie に変え -th をつける
*40 (forty) → 40th (fortieth)

5. その他
*1 (one) → 1st (first)
*2 (two) → 2nd (second)
*3 (three) → 3rd (third)
*9 (nine) → 9th (ninth)

6. 2桁以上の数は、 最後の数字だけを序数詞にする
*31 (thirty-one) → 31st (thirty-first)
*42 (forty-two) → 42nd (forty-second)
*53 (fifty-three) → 53rd: (fifty-third)
*25 (twenty-five) → 25th: (twenty-fifth)
*39 (thirty-nine) → 39th (thirty-ninth)
*88 (eighty-eight) → 88th (eighty-eighth)
*123 {one hundred (and) twenty-three}
→ 123rd {one hundred (and) twenty-third}

「電話番号」「郵便番号」「部屋番号」「番地」などの英語の言い方

「知っていると便利な日付の書き方、読み方」「誕生日の言い方」「西暦の言い方」