fifteenth的音標是[?fif?nθ??(r)]，基本翻譯是第十五，速記技巧是：諧音“費吩惜”。

fifteenth這個詞的詞源可以追溯到拉丁語詞匯“quindices”，意為“第十五”。它的變化形式主要有復數形式“fifteenths”和過去式“fifteendeth”。

相關單詞：

1. “fifteen”是它的原型，表示十五，是數量詞。

2. “fifteenth”可以作為形容詞，表示第十五的。

3. “fifteendeath”可以表示十五個死亡，或者處以死刑。

4. “fifteens”是它的復數形式，可以表示十五個或十五塊錢。

5. “fifteenth-century”表示十五世紀，可以用來描述某個時間段的特定歷史時期。

6. “fifteenth-anniversary”表示十五周年紀念日，用來慶祝某個重要事件或成就的周年紀念。

7. “fifteenth-month”表示第十五個月，可以用來描述某個時間段內的月份。

8. “fifteenth-century Europe”表示歐洲十五世紀的歷史時期。

9. “fifteenth-rate”表示低劣的品質或等級，通常用來形容某個事物或人的品質或能力。

10. “fifteenth-hand”表示二手的，通常用來形容某個物品已經使用過一段時間或者已經被多次轉手。

在英語中，fifteenth這個詞的使用非常廣泛，它不僅可以幫助我們理解歷史背景和文化內涵，還可以幫助我們更好地理解和使用其他相關的詞匯和短語。

常用短語：

1. fifteenth floor

2. fifteenth birthday

3. at the fifteenth minute

4. on the fifteenth day

5. in the fifteenth century

6. the 15th of every month

7. the 15th of July

例句：

1. The elevator arrived on the fifteenth floor.

2. It was my sister"s fifteenth birthday and we had a party.

3. We had to work until the fifteenth minute of the hour.

4. After a month, it was on the fifteenth day of the month.

5. In the fifteenth century, people believed in magic.

6. She always remembers to write a letter on the 15th of every month.

7. The 15th of July is a public holiday in many countries.

英文小作文：

Today is my fifteenth birthday, and I feel very happy and excited. I have been looking forward to this day for a long time because it means I am now a year older and wiser. I have learned so many new things and made some great friends since last year. I am also looking forward to what the future holds for me because I am sure it will be filled with many wonderful experiences and opportunities. As I grow older, I realize how important it is to cherish every moment and to make the most of every opportunity that comes my way. Today, I will celebrate my birthday with my family and friends and enjoy every minute of it.