Student or Learner
1. If I could have stopped, there wouldn't have been an accident.
2. If I had been able to stop, there wouldn't have been an accident.
Is sentence 1. a good written form? I wonder whether sentence 1. is acceptable in the TOFEL test.
Many many thanks in advance.
Sentence 2 is more correct than sentence 1.
For sentence 1, it sounds better to say:
"If i had stopped, there wouldnīt have been an accident". I donīt think it would be acceptable to say it the way you did.