1. A proposal for a school trip was typed by Richo. (Simple Past)

2. A problem were being discussed by Fani and Fika when I arrived. (Past Continuous)

3. The door had been locked by Edo before he left his house. (Past Perfect)

4. An announcement will be delivered by the Teacher this afternoon. (Simple Future)

Penjelasan:

Berikut rumus untuk mengubah active voice menjadi passive voice sesuai tenses:

a. Simple present: to be (are/ am/ is) + verb 3 + by

b. Simple continuous: to be (are/ am/ is) + being + verb 3 + by

c. Simple past: past to be (were/ was) + verb 3 + by

d. Past continuous: past to be (were/ was) + being + verb 3 + by

e. Present perfect: auxiliary verb (have/ has) + been + verb 3 + by

f. Past perfect: auxiliary verb (had) + been + verb 3 + by

g. Simple future: auxiliary verb (will) + be + verb 3 + by

h. Conditional present: auxiliary verb (would) + be + verb 3 + by

i. Conditional past: auxiliary verb would have + been + verb 3 + by

j. Present infinitive: to + be + verb 3 + by

k. Present participle: being + verb 3 + by

l. Perfect participle: having been + verb 3 + by

Semoga membantu, ya