It is true that the passive voice is most talked about by our students. I think we can go beyond the formal grammar rules and deal with it in the funniest way. That's -between us- a sort of word games. Let's enjoy talking about the passive voice in the absence of Mr R.G.R (Rigid Grammar Rule). We will be back biters for a while, yet I hope in the benefit of both The Passive Voice and our students.
Let's make one of the old so missed rules our starting point. The rule says: the object of the active sentence is always the subject of the passive one. But before all let's see what does the active sentence look like before the operation then go to discuss the process the doctor follows during the operation and examine the patient after the operation. It is not an easy work to do, I admit it.
<<The passive voice of any transitive verb is made by combining its past participle with the appropriate tense of the verb "to be" >>, the teacher said. He means that the verb “to be” is always the doctor who can operate on the sentence successfully in a "passive voice" surgery. Take this so called the patient active sentence, for instance,
Someone plays the piano every night
This sentence is composed of a subject: (someone), a verb: (plays), and an object (the piano). And the latter is the organ that gears the whole operation. It is the most important part of the utterance to make the operation feasible.