Passive voice is formed by changing the subject of the active voice as a complement and the object of the predicate as the subject.
1. All of us were surprised to hear the views that were expressed by him.
Active voice: “All of us were surprised to hear the views that he expressed”
2. At each new performance of the jazz band, the music was enjoyed by Pat even more.
Active voice: “At each new performance of the jazz band, Pat enjoyed the music even more.”
3. Several different techniques for grafting can be employed by the gardener.
Active voice: “The gardener can employ several different techniques for grafting.”
4. Only one person had not been persuaded by the rhetoric.
Active voice: “The rhetoric had not persuaded only one person.”