When we want to change a statement from active to passive, in the present continuous, we have to change the verb that is continuous from the active verb to the continuous for of be and the past participle of the active verb.
E.g. if we start with is painting then we have to change it to is being painted by.
However I'm not sure how to change the subject and the object. If we start with:
John is painting his room.
Is the passive construction:
His room is being painted by John.
Something seems wrong when comparing the two sentences, but I'm not sure what. Does his in the passive construction refer to the same person as in the active?