Answer:
1. The boy killed the spider.
Passive: The spider was killed by the boy.
2. Help him.
Passive: N/A (No object. The object is changed to the subject while changing to passive voice. Without a subject, a sentence cannot be changed to passive. And, a command can't, either.
3. Farmers sow maize in the rainy season.
Passive: Maize is sowed by farmers in the rainy season.
4. Are you writing a letter?
Passive: Is the letter being written by you?
5. The workers were digging a canal.
Passive: A canal was being dug by the workers.
Explanation:
