1. Why don't you study hard?

`→` If I were you,I would study hard 

2. If I have time, I'll help you.

`→` Unless I have time , I won't help you

*Câu điều kiện loại 1 : If + mệnh đề hiện tại đơn, S + will+ V + O 

`→` Unless= If...not : (Nếu ………không, trừ phi)

1. If I were you, I would study hard.

If 2: If + QKĐ, S + would / could + V1 

QKĐ V-to be: S + was/were 

QKĐ V-thường: S + V2/ed

2. Unless I have time, I won't help you.

If 1: If + HTĐ, S + will/can/shall.. + V1 

Unless (trừ khi) = If ... not (nếu không ... thì)

`color{orange}{~LeAiFuRuiHuiBao~}`