The document discusses active and passive voice in English grammar. It explains that active voice uses the normal subject-verb-object structure, while passive voice focuses on the subject receiving the action. Passive voice uses the formula of subject + to be verb + past participle. Examples are provided to illustrate how to change sentences from active to passive voice in different tenses, including present simple, past simple, present perfect, present continuous, past continuous, and future simple. Guidelines are also given for when to omit "by" in passive voice sentences that do not specify the actor. Practice exercises at the end demonstrate how to change active sentences into passive sentences.

1. By
Mrs.Worawan Rueangpayoongsak
in
Fundamental English 3 (En 32101)
M. 5/1 – 5/5
Foreign Languages Department
Active & Passive

2. Active Voice คือ ประโยคธรรมดาที่เราใช้พูดกัน
Sub.+ V. + Obj. or Modifier
• Passive Voice คือประโยคที่เน้นว่าประธานถูกกระทา
• รูปแบบของ Passive คือ Sub. + V.to be + V.3
• V. to be สามารถเป็นได้ตาม Tense ต่างๆ ว่าถูก
กระทาช่วงเวลาใด

3. Present Simple (ถูกกระทาในปัจจุบัน)
is/ am/ are + V.3
Example :
Active : Mary writes a letter today.
Passive : A letter is written by Mary today.

4. Past Simple (ถูกกระทาในอดีต)
was/ were + V.3
Example :
Active : Mary wrote a letter last night.
Passive : A letter was written by Mary last night.

5. Present Perfect
(ถูกทาลงไปแล้วแต่ไม่ได้ระบุเวลา หรือ ถูกทาเรื่อยมาจนถึงปัจจุบัน)
has/ have + been + V3
Example :
Active : Mary has just written a letter.
Passive : A letter has been just written by Mary.
Active : Mary has written a letter for 1 hour.
Passive : A letter has been written by Mary for 1 hour.

6. Present Continuous (กาลังถูกกระทาในปัจจุบัน)
is/ am/ are + being + V.3
Example :
Active : Mary is writing a letter now.
Passive : A letter is being written by Mary now.

7. Past Continuous (กาลังถูกกระทาในอดีต)
was/ were + being + V.3
Example :
Active : Mary was writing a letter at 9 pm. Last night.
Passive : A letter was being written by Mary at 9 pm. last night.

8. Future Simple (ถูกกระทาในอนาคต)
will/ shall + be + V.3
Example :
Active : Mary will write a letter tomorrow.
Passive : A letter will be written by Mary tomorrow.
สาหรับ กริยาช่วยตัวอื่นๆก็ทาได้เหมือนรูปแบบ will/ shall เช่นกัน เช่น
can, may, must, should, ought, need, dare etc. เช่น
Active : Mary can write a letter .
Passive : A letter can be written by Mary.

9. ข้อควรสังเกต ถ้าประธานเป็น They / someone /
anyone/ somebody/ everybody etc.
เมื่อเป็นประโยค Passive ไม่ต้องใช้by
เพราะไม่ได้ระบุแน่นอนว่าใครเป็นผู้กระทา
Example :
Active : They hit the tennis balls at the court.
Passive : The tennis balls are hit at the court.
(ไม่ได้ระบุชัดเจนว่า they เป็นใคร)

10. Practice the exercise.
Change the active sentences into the passive sentences.
1. I read a book every day.
…………………………………………………………………….
2. He will send the e-mail in the evening.
……………………………………………………………………………..
3. Sam has repaired the door since 9 am.
……………………………………………………………………………...

11. 4. They are playing football in the field now.
…………………………………………………………………………..
5. She was cleaning a toilet at 10 am. last Saturday.
…………………………………………………………………………..
6. Our company sends the parcels to the clients once a week.
………………………………………………………………………………………….
7. The horse kicked the naughty boy yesterday evening.
…………………………………………………………………………………………..
8. I will order pizza tomorrow.
…………………………………………………………………………………………..
9. We speak English every day.
…………………………………………………………………………………..........
10. Ben likes coffee and tea.
………………………………………………………………………………............

12. Keys
1. A book is read by me every day.
2. The e-mail will be sent by him in the evening.
3. The door has been repaired by Sam since 9 am.
4. Football is being played in the field now.
5. A toilet was being cleaned by her at 10 am. last Saturday.
6. The parcels to the clients were sent by our company once a week.
7. The naughty boy was kicked by the horse yesterday evening.
8. Pizza will be ordered by me tomorrow.
9. English is spoken by us every day.
10. Coffee and tea are liked by Ben.