Step 1: Changing sentence into Passive voice.
In passive voice, the object of the active sentence becomes the subject, and the subject becomes the agent, preceded by "by." The verb is changed accordingly, and the question mark remains. The auxiliary verb changes to the correct form based on the subject and tense.
Step 2: Passive voice for sentence (i):
Was he seen by you yesterday?
Step 3: Conclusion.
The passive voice form of the given sentence is:
Was he seen by you yesterday?