$1$. If he didn't have to study for his exam,he could go out.
$2$. If she weren’t lazy, she could pass the exam.
$3$. If he pays me tonight, I will have enough money to buy a car.
$4$. If he didn't smoke too much, he could get rid of his cough.
$5$. If she was not very shy, she would enjoy the party.
$6$. If he took exercises, he would be healthy.
$7$. If you study hard, you will pass the exam.
$8$. If you are not impatient, you will make mistakes.
$9$. If I had eaten lunch, I wouldn't feel hungry now.
$10$. If I were you, I would not buy it.
$11$. Unless they invite me, I will not come.