1.. They used my computer to make a presentation last week.

=> My computer was used to make a presentation last week

2. People used this kind of the plant to produce medicine.

=> This kind of plant was used to produce medicine.

3. The students used the discarded paper to make this flowers.

=> The discarded paper was used to make this flowers by the students.

4. The children used water colours to draw pictures.

=> Water colours were used to draw pictures by the students

Các câu bị động trên là câu bị động của thì QKĐ

S + V_ed -> S + was/were + Vp2

CẤU TRÚC 3: BỊ ĐỘNG PEOPLE SAID THAT

1. They report that two people were injured in the explosion.

=> Two people are reported to have been injured in the explosion.

2. People say that three children were lost in the jungle.

=> Three children are said  to have been lost in the jungle.

3. They report that four Vietnamese students were recognized as the Outstanding Students of the world.

=> Four Vietnamese students are reported to have been recognized as the Outstanding Students of the world.

4. People believe that the church was built in 13th century.

=> The church is believed to have been built in 13th century.

Nếu động từ V1 chia thì hiện tại đơn và V2 chia thì quá khứ đơn: 

S2 + is/am/are + V1-PII + to have + V2-PII + O 

Vì động từ V2 chia ở thể bị động nên phải chuyển thành “to have been Vp2"