我们英语书上有一句话是Someone saw him walk into that building at about three this afternoon.

题目

我们英语书上有一句话是Someone saw him walk into that building at about three this afternoon.
为什么句中要用walk,而不用walking,有一句型不是see sb doing sth

答案

两个都可以,但强调的不同.用walking强调的是看到他走进去的状态,用walk强调的是看到他走进去的事实.