passive voice

Passive voice menunjukkan apa yang dilakukan terhadap subjek. Contoh:
1. The letter was written by the secretary (Surat ditulis oleh sekreatir)

Kalimat pasif dibuat dengan kata kerja “to be” dan kata kerja bentuk ke-3. Berikut beberapa tenses bahasa Inggris utama yang digunakan dalam passive voice.

Tenses	Subject	Verb “to be”	Verb III
Simple present	Flowers	are	planted every year
Present continuous:	Flowers	are being	planted now.
Simple past:	Flowers	were	planted last year
Past continuous	Flowers	were being	planted last summer.
Present perfect	Flowers	have been	planted here for 10 years
Past perfect:	Flowers	had been	planted until last year
Future:	Flowers	will be	planted next year.
Future continuous:	Flowers	will be being	planted during the summer
Present conditional:	Flowers	would be	planted if we had seeds.
Past conditional:	Flowers	would have been	planted if we had had seeds.

• Active : We fertilize the soil every 6 months
• Passive: The soil is fertilized by us every 6 months

cara mengubah kalimat aktif menjadi pasif :
1.  Object dari active voice (the soil) menjadi subject dari passive voice 2.
2. Subject dari active voice (we) menjadi object dari passive voice. Perhatikan pula bahwa terjadi perubahan dari subject pronoun ‘we’ menjadi object pronoun ‘us’.
3. Verb1 (fertilize) pada active voice menjadi verb3 (fertilized) pada passive voice.
4.  Ditambahkannya be ‘is’ di depan verb3. Be yang digunakan adalah tergantung pada subject passive voice dan tenses yang digunakan. (Perhatikan pola-pola passive voice di bawah).
 5. Ditambahkannya kata ‘by’ di belakang verb3. Namun, jika object dari passive voice dianggap tidak penting atau tidak diketahui, maka object biasanya tidak dikemukakan dan begitu pula kata ‘by
6.  Khusus untuk kalimat-kalimat progressive (present, past, past perfect, future, past future, dan past future perfect continuous, perlu menambahkan ‘being’ di depan verb3). Kalau tidak ditambahkan “being”, tensisnya akan berubah, bukan progressive/continuous lagi. Perhatikan contoh-contoh pada poin h – o di bawah

contoh-contoh pasif:
1. I was born in Iran.
2. The twins were born just last year.
3. He is liked by a lot of people
4. She is known to be a hard-working employee
5. They are met by him everyday

1. Jack sings a song (active)
2. A song is sung by Jack (Passive)

1. Jack sang a song yesterday (active)
2. A song was sung by Jack yesterday (passive)

1. Jack has sung a song (active)
2. A song has been sung by Jack (passive)

1. Jack will sing a song (active)
2. A song will be sung by Jack (passive)

1. Jack is singing a song (active)
2. A song is being sung by Jack (passive)

1. Jack can sing a song (active)
2. A song can be sung by Jack (passive)

 sumber : http://gitaanggeliya.blogspot.com/2011/03/contoh-kalimat-passive-voice.html
               http://englishonline.blogdetik.com/2009/08/18/passive-voice/