Adding or omitting "from".

How does a person know when to omit or add the preposition in such constructions?

These are American English examples.

'Ms. Gawanas made the same point as Albie Sachs about people knowing what happened. # " We need to know to prevent it happening again, " she said. " People here did not vote to wipe history off when they approved the Constitution.'

Title AT HOME ABROAD;Revenge or Reconciliation?
Author By Anthony Lewis
Source New York Times


.......

"And the Europeans said all right, let's give us another month, or two, or three. Essentially, what the Europeans have done is prevent it ending up at the Security Council and prevent any sanctions."

Title All-Star Panel Discusses Separate Peace Europeans have with the Axis of Evil
Source Fox_Hume


-------

"and admitting, quite insolently, that they hadn't practiced since last week, all the while daring plain Miss Muriel Fraser to find a punishment strong enough to interest them in art while remaining mild enough to prevent her being fired."

Title The Practical Heart
Author Gurganus, Allan
Source Harpers Magazine

I've gotten the impression that omitting "from" in these contexts is more common in Britain. Take these Google results, for example:

"realize" "prevent him from going": 717
"realize" "prevent him going": 251

"realise" "prevent him from going": 649
"realise" "prevent him going": 1,730

I don't think there's any solid rule on this, so I think there's room for free variation; my own tendency (as an AmEng speaker) is to keep the "from" in most situations.

This is what I got from the BNC.

1 PREVENT THEM FROM GOING 4
2 PREVENT HIM FROM GOING 3
3 PREVENT US FROM GOING 1
4 PREVENT HERSELF FROM GOING 1
5 PREVENT HER FROM GOING 1
TOTAL 10
...........................................................

1 PREVENT IT GOING 3
2 PREVENT THEM GOING 2
3 PREVENT US GOING 1
4 PREVENT HIM GOING 1
5 PREVENT HER GOING 1
TOTAL 8