IT'S VERY EASY AND SIMPLE ....
TO UNDERSTAND THE PASSIVE VOICE, LOOK AT THE SENTENCE BELOW
WHAT ARE THE CHANGES?
HAS CHASED -----> HAS BEEN CHASED
WILL CHASE -----> WILL BE CHASED
THE CHANGES THAT THE VERB ''TO BE'' TAKES IN THE PASSIVE FORM WILL BE AS IN PICTURE
Important Remark: { IT IS + P.P .... THAT ...} / { SUBJ + IS +P.P + TO BE .....}