1. Though panels are quite expensive to install, you'll save money on electricity in the end.

- Clause 1 (S + V + O), but + Clause 2 (S + V + O): nhưng

=> Though + Clause 1 (S + V + O), Clause 2 (S + V + O): mặc dù

-> Thì HTĐ: (+) S + is/am/are + N/Adj

-> Thì TLĐ: (+) S + will + V(bare)

2. Train tickets are as cheap as bus tickets.

- S1 + and + S2 + be + both + adj: cả hai

=> So sánh ngang bằng: S1 + be + as + adj + as + S2

-> Thì HTĐ: (+) S + is/am/are + N/Adj

3. Students need to/ have to hand in their assignments on time.

- It's necessary + for sb + to V: nó là cần thiết cho ai đó để làm gì đó

=> S + need to/ have to + V(bare): ai đó cần/ phải làm gì đó

4. You should drink enough water every day.

- It's a good idea + to V: nó là một ý tưởng hay để làm gì đó

=> S + should + V(bare): ai đó nên làm gì đó

-> Though pannels are quite expensive to install, you'll save money on electricity in the end

- Although/Though/ even though + clause

- - Although/Though/ even though: Mặc dù: diễn tả 2 mệnh đề có nội dung tương phản

-> Train tickets are as cheap as bus tickets

- So sánh bằng: S1 + be/V + as adj/adv as S2

-> Students have to hand in their assignments on time

- Have to: nên (theo yếu tố khách quan như luật lệ, các yếu tố tác động từ ngoài)

-> You should drink enough water every day

- Should: nên (theo yếu tố chủ quan)