Grammar: Passive voice - Thể bị động

Some reasons to use The passive voice in Vietnamese language:

1/ Subject (the actor) is not important / obvious/ unknown

Con sư tử đã bị giết

The lion was killed. -> We don't know who killed the lion (Unknown), or the person who killed it was not important in our sentence/conversation (Not important)

Căn phòng đã được lau dọn

The room was cleaned -> We know the person who cleaned the room because he/she does it every day (Obvious)

Con đường đã được sửa chữa

The road was repaired (Who repaired it? -> Who cares?. It is repaired, and this is more important)

2/ To shift focus of subject

Insulin đã được các nhà nghiên cứu ở đại học Toronto phát hiện ra vào năm 1921

Insulin was first discovered in 1921 by researchers at the University of Toronto.

(We want to talk about Insulin. We want Insulin to be the subject. We don’t really care about The researchers at University of Toronto. We put the focus on Insulin. Other information comes later)

3/ An impersonal tone is needed for academic writing.

Thủy tinh được xếp vào loại chất rắn

Glass is classified as a solid.

4/ Reports of crimes or incidents with unknown perpetrators

Xe hơi của tôi đã bị lấy cắp hôm qua

My car was stolen yesterday

5/ Must use The passive voice.

Nam bị thương trong một tai nạn xe hơi

Nam was injured in a car accident.

It is Weird/Awkward to say “Một tai nạn xe hơi làm tổn thương Nam”

A car accident injured Nam

6/ Creating a flow in a paragraph/story