$\text {·He can't go out because he has to study for his exam}$
$\text {→If he didn't have to study for his exam, he could go out}$
$\text {·Dịch: Nếu anh ấy không phải học cho kỳ thi của mình, anh}$
$\text {ấy có thể ra ngoài}$
$\text {Chúc bạn học tốt~}$
$\text {@lamtung2}$