his job is to sweep the floor. his job is sweeping the floor. 有什么区别? 是不是两种都可以,为什么

题目

his job is to sweep the floor. his job is sweeping the floor. 有什么区别? 是不是两种都可以,为什么
如果不是,那用哪一种?
谢谢O(∩_∩)O~

答案

两种都可以,to sweep the floor是动词不定式,sweeping the floor是动名词,两者都可以作表语.