$4$. Unless you study hard, you won’t pass the exam
`->`Unless=If not: Nếu không
`->`Unless + S + V, S + will/can + (not) + V
$5$. He prefers listening to pop music to watching TV after school
`->`prefer + V-ing + to + V-ing: thích cái gì hơn cái gì
$6$. My brother used to study more lazily than he does now
`->`CT câu so sánh hơn với tính từ dài: S + V/tobe + more + adv/adj + than + O