“both”和“both of”均用于指代两个事物或人,但语法用法不同。接名词时,“both”直接修饰名词无需限定词(如the、物主代词等),例“Both books are interesting”;“both of”后接名词需加限定词,例“Both of the books are interesting”。接代词时,“both”后用主格,例“Both are good at math”;“both of”后用宾格,例“Both of them are good at math”。位置上,“both”...