1/ Keep silent or you’ll wake the baby up.
→ If you don't keep silent, you will wake the baby up.
2/ Stop talking or you won’t understand the lesson.
→ If you don't stop talking, you won't understand the lesson.
3/ I don’t know her number, so I don’t ring her up.
→ If I knew her number, I would ring her up.
4/ I don’t know the answer, so I can’t tell you.
→ If I knew the answer, I would tell you.
5/ Peter is fat because he eats so many chips.
→ If Peter didn’t eat so many chips, he wouldn't be fat.
6/ If you are not careful, you will cut yourself with that knife.
→ Unless you are careful, you will cut yourself with that knife.
7/ If you do not like this one, I’ll bring you another.
→ Unless you like this one, I’ll bring you another.
8/ The weather isn’t fine now. We can’t go for a walk.
→ If the weather were fine, we could go for a walk.
9/ I don’t live in a big city, so I can’t go to the cinema very often.
→ If I lived in a big city, I could go to the cinema more often.
10/ Lan doesn’t have a bike, so she walks to school.
→ If Lan had a bike, she would ride it to school.