difference between "I saw him cross the bridge" and "I saw him crossing the bridge"

[keannu]

Some grammar books explain the difference between the two sentences like this.
1. I saw him cross the bridge. (I watched the whole action from him going from the entrance to the ending point of the bridge)
2. I saw him crossing the bridge.(I watched him at some point of moving)

Is it really what native speakers perceive and think or do they make little difference in meaning?
A kind help will be highly appreciated.

[DavidA]

I am not an English teacher.

But I am a native English speaker. It is true that the first example suggests the complete action was seen, and the second that only part of it was, but to a native English speaker, this detail is extremely pedantic and in general usage they mean virtually the same thing.

[opa6x57]

Not a teacher, but native American English speaker for 53 years.

If I were an observer to some EVENT which involved participants moving through a specific course, I MIGHT say, "I saw him cross the bridge." thus indicating I saw him complete this portion of the entire course.

I would be much more likely to report that "I saw him as he was crossing the bridge." indicating that I happened to see him at some point while he was crossing the bridge.

To me there is a difference in meaning between the two. I would most likely use 'crossing' if I saw him at any point along the bridge.

I would use 'cross' only if I either saw him through the entire trip over the bridge, or if I witnessed the COMPLETION of the trip across the bridge.

That's my opinion.

[maapaa]

A teacher - but not native American English speaker.

For me it's all about the duration of what you are doing.
If you walk along a river, look around and see somebody entering a bridge, crossing the bridge and leaving it on the other side ... then I would call it "I watched him cross the bridge" (from the start until the end).
But if you walk along a river, look around and see somebody at any point on the bridge, turn your head away from him and go on your way - then I would call it "I saw him crossing the bridge" (for a moment).

Not sure if my comment is helpful, right or even wrong.


Thanks for reading