May failed the exam because she didn't revise	If May had revised, she might have passed the exam.	
Gilbert has terrible breath because he never cleans his teeth.	If Gilbert cleaned his teeth, he wouldn't have terrible breath.	
The burglar was caught because he left fingerprints in the house.	If the burglar hadn't left fingerprints in the house, he wouldn't have been caught.	
Candy married the old man because he is stinking rich.	If the old man wasn't stinking rich, Candy wouldn't have married him.	
Kenny put some money in the collection box because he was with his girlfriend.	If Kenny hadn't been with his girlfriend, he wouldn't have put any money in the  collection box.	
Mavis got a good mark for her assignment because her brother wrote it for her!	Mavis wouldn't have got a good mark for her assignment if her brother hadn't written it for her.	
Donald was nice to his sister because he wanted to borrow her car.	Donald wouldn't have been nice to his sister if he hadn't wanted to borrow her car.	
Wilson didn't keep the old vase because he didn't know it was priceless.	If Wilson had known the old vase was priceless, he would have kept it.	
Derek didn't go to the party because he didn't know Suzie would be there.	If Derek had known Suzie would be at the party, he would have gone.