Both 可作限定词 （det），意思为：二者，两者都， 用英语解释为：each of two; one and the other Both books are thick. 两本书都很厚。
可作为连词 (conj.) ，意思为：不仅…而且…，…和…都, 一般的形式为both..and... 用英语解释为： the structure both...and is used to give two facts or alternatives and emphasizing that each of them is true or possible Both you and I are students. 你和我都是学生。