in fact I don't find a passive form to use to turn a sentence that has a verb in the present perfect continous tense(have/has + been + v-ing) from active into passive so I always answer the question"what is the passive form from the present perfect continous?"as it is the same as the passive form from the present perfect simple itself. Could anyone correct my information,please?
You could be right. Thereíre 12 tenses in the active voice, but only 8 in the passive. We donít have passive for future continuous (that being one) and present, past and future perfect continuous (that being 3). As can be seen, PPC is one of them.