cross v-s crossing

English as a Second Language English Vocabulary, Grammar and Idioms
1

hello there. it would be great if anyone could help me to see the difference between these two sentences:

  1. I saw the policeman cross the street
  2. I saw the policeman crossing the street
    thanks in advance
2

My take:
In #1 you merely state the fact that the policeman crossed the street (you saw him).
In #2 not only did you see him, but you were actually watching the policeman as he was crossing the street, you saw his movements/steps, etc. In other words, you were paying close attention to him while he was moving across the road.

3

I don’t think the average native English speaker would consider the distinction, though.

4

When you see someone do something, you see it completely. But when you see someone doing something, you do not see it completely. “I saw a policeman cross the road” means that you saw his crossing of the road completely. When he arrived at the other end of the road, you ceased to look at him. “I saw a policeman crossing the road” means that you saw the starting of the crossing of the road by the policeman but you do not know whether he crossed the road or not. Because before his completion of the crossing, you ceased to look at him.
O.ABOOTTY

5

Hi Roman,

There is a distinction, as has been explained above. The point is that native speakers would use this distinction instinctively.

Alan