Ly thuyet bi dong so luoc

* Thể chủ động (active voice) là câu mà chủ từ đóng vai trò chủ động
* Thể bị động (pasive voice) là cách đặt câu mà chủ từ đóng vai trò bị động
Active sentence: S + V + O
( Passive sentence : S + be + V3/ED (by O)
E.g.: * Active : Tom broke the chair yesterday.
S V O
* Passive : The chair was broken by Tom yesterday.
S be + V3/ED by doer
( Ghi nhớ: Cách đổi một câu từ chủ động sang bị động
Lấy O trong câu chủ động xuống làm chủ từ trong câu bị động
Nhận diện xem động từ chia ở thì nào, chia To Be ở thì đó rồi viết động từ chính ở dạng quá khứ phân từ (V3/ED)
Lấy chủ từ ở câu chủ động xuống làm tân ngữ trong câu bị động, nhớ thêm BY ngay trước
Trạng từ giữ nguyên không đổi và thường được đặt ở cuối câu (nếu là trạng từ chỉ thời gian
E.g.:
+ (a) simple present : [Subject+ am / is / are + V3/ED ] - Mr.Green teaches history. ( History is taught by Mr.Green.
+ (b) present perfect : [ S + has / have + been + V3/ED ] - He has just done his homework. ( His homework has just been done by him.
+ (c) present continuous : [ S + am / is / are / + being + V3/ED] - She is cleaning the windows. ( The windows are being cleaned by her.
+ (d) simple past : [ S + was / were + V3/ED] - The boss sacked ten workers. ( Ten workers were sacked by the boss.
+ (e) past perfect : [ S + had been + V3/ED] - Mary had written the letter. ( The letter had been written by Mary.
+ (f) Past continuous : [ S + was / were + being + V3/ED] - The police were questioning Tom. ( Tom was being questioned


by the police.
+ (g) simple future: [ S + will / shall + be + V3/ED] - John will deliver the letter. ( The letter will be delivered by John.
+ (h) Modal verbs : [ S + must / can / may … + be +V3/ED] - He must do it right now. ( It must be done by him right now.
+ (i) special structures : [ S + is / are going to + be +V3/ED]
- The engineers are going to build the bridge. ( The bridge is going to be built by the engineers.
(…….. còn áp dụng với các cấu trúc khác như: have to, had to, used to, ought to …)
+ (j) 2 objects :
- They gave me a present yesterday. ( I was given a present yesterday(by them). ( A present was given to me yesterday(by them).
(Nếu sau BY làø them / people / someone / somebody …. ta có thể bỏ đi)
+ (k) perception verb with bare infinitive : [ S + be – V3/ED + to inf ]
- I never hear him shout at his children. ( He is never heard to shout at his children.
+ (l) perception verb with present partciple : [ S + be – V3/ED + V-ing ]
- I saw the boy coming into the room. ( The boy was seen coming into the room.
+ (m) With ‘make’ : [ S + be – made + to inf ]
- They made me do it. ( I was made to do it.
+ (n) With ‘let’ : [ S + be – let + bare inf ]
- They let him do it. ( He was let do it.
+ (o) With ‘begin or start’: [ S + begin / start + to be + V3/ED ]
- They began to build the house in 1980. ( The house began to be built in 1980.
+ (p) With “say, report, rumour…’:
- People say that prevention is better than cure. ( It is said that prevention is better than cure.
( Prevention is said to be better than cure.
(… cách đổi này được áp dụng cho các động từ sau SAY, REPORT, THINK, BELIEVE, RUMOUR…)
by the police.
+ (g) simple future: [ S + will / shall + be + V3/ED] - John will deliver the letter. ( The letter will be delivered by John.
+ (h) Modal verbs : [ S + must / can / may