***** NOT A TEACHER *****
Many books tell us that one of the purposes of the passive is to make our questions less harsh.
ACTIVE: Who is leaving the lights on at night?
PASSIVE: Why are the lights being left on at night (by someone)?
ACTIVE: Who ate the last piece of lemon pie?
PASSIVE: I have just noticed that the last piece of lemon pie has been eaten (by a very selfish person)!
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