十五英文怎么说怎么写

"十五"在英语中说作 "fifteen"，写作 "15"。

"Fifteen"来源于古英语"fif"和"teen"的结合，"fif"意为"five"，"teen"意为"ten"，即"十五"。

例句：

My sister is fifteen years old. (我的妹妹十五岁。)
There are fifteen people in this class. (这个班有十五个人。)
I will be fifteen years old next week. (下周我就十五岁了。)