If you do not keep silent, you will wake the baby up.
you do not stop talking, you won't understand the lesson. 
you do not study hard, you won't pass the exam.
do not give him some advice, he won't know what to do. 
I knew her number, I would ring her up. 
I knew the answer, I would tell you. 
we had a map, we wouldn't get lost. 
If Susan did not eat four cream cakes, she would not feel sick.