1. He can’t go out because he has to study for his exam.
-> If he didn’t have to study for his exam, he could go out.
2. She is lazy so she can’t pass the exam.
-> If she weren’t lazy, she could pass the exam.
3. She is very shy, so she doesn’t enjoy the party.
-> If she weren’t shy, she would enjoy the party.
4. He doesn't take any exerciese. He is so unhealthy.
-> If he took exerciese. He would be healthy
5. Study hard or you won't pass the exam
-> If you don't study hard, you won't pass the exam
Giải thích:
If + S + V(hiện tại), S + will/won't/would + V(infi).
If + S + V(quá khứ), S + would/could/should + V(infi).
