比我小三岁用英语怎么说

"Three years younger than me" 可以用英语表达为 "Three years younger than I" 或 "Three years younger than myself"。这种表达方式源于英语语法中关于比较级的用法。
例句1: "My sister is three years younger than I." (我的妹妹比我小三岁。)
例句2: "John is two years older than his brother, but five years younger than me." (约翰比他哥哥大两岁，但比我小五岁。)
例句3: "I'm the same age as my best friend, but my sister is three years younger than me." (我和我最好的朋友一样大，但我的妹妹比我小三岁。)