15

grammar · medium

易错句子I have 15 years old.

正确表达I am 15 years old.

英语说年龄用 be 动词，不用 have；‘我十五岁’不能直译为 I have 15 years old，应说 I am 15 years old。

grammar · medium

易错句子He is a 15 years old boy.

正确表达He is a 15-year-old boy.

数词作定语修饰名词时，要用连字符组成复合形容词，且 year 用单数：a 15-year-old boy，而不是 a 15 years old boy。

grammar · medium

易错句子There are 15 of students in the classroom.

正确表达There are 15 students in the classroom.

表示数量时，数词直接修饰复数名词，不需要 of；只有后接限定词或代词时才用 of（如 15 of the students / 15 of them）。