1. I wish I had been more careful using the knife.
If I had been more careful using the knife, I wouldn't have cut my finger.
2. I can't climb the mountain because I'm afraid of heights.
I wish I could climb the mountain, but I'm afraid of heights.
If I weren't afraid of heights, I would climb the mountain.
3. I can't play outside because I'm ill.
I wish I weren't ill, so I could play outside.
If I weren't ill, I would play outside.
4. I've got sunburn. I shouldn't have stayed in the sun for so long.
I wish I hadn't stayed in the sun for so long.
If I hadn't stayed in the sun for so long, I wouldn't have got sunburn.
5. I didn't look where I was going and I bumped my head.
I wish I had looked where I was going.
If I had looked where I was going, I wouldn't have bumped my head.