=>
1. Van hasn't written to his pen pal for 5 months. (QKĐ chuyển sang HTHT have/has V3/ed, for + khoảng time)
2. People use computers to design new models. (bị động chuyển sang chủ động ở thì HTĐ S Vs/es)
3. Students do not have to wear uniforms today.(don't have to = don't need to = It isn't necessary for sb to V)
4. I wish your friend were at this party. (câu ước, lùi thì HTĐ -> QKĐ)
5. That model isn't being used by the teenagers these days. ( bị động HTTD is/am/are being V3/ed)
6. I'll finish the work tonight if you want. (câu đk loại 1 S will V if S Vs/es)
7. I prefer reading newspapers to watching TV (prefer Ving to Ving : thích gì hơn)
8. He is used to writing with both his hands. (be used to Ving : quen làm gì)

7. I prefer reading newspaper to watching TV. ( công thức của prefer: S + prefer + V-ing + to + V-ing)

Chúc bạn học tốt!!!