They talked about the problem. → The problem was talked about.
Someone has slept in this bunk. → This bunk has been slept in.
不過將「Someone has slept above this bunk.」變為「This bunk has been slept above.」的做法接受度不高,因為「sleeping above a bunk」不改變bunk的狀態,而been slept above沒有提到bunk的「相關重要的性質」。而一般直覺上會在動詞片語表達主詞的「相關重要的性質」時使用Prepositional passive,而這是Prepositional passive的一個限制(Intuitively, you use a prepositional passive when the VP expresses a relevantly important property of the subject. That's a restriction on prepositional passives)
Prepositional passive似乎只能用於不及物動詞。也就是像將「Someone has put a child in this bunk.」變為「*This bunk has been put a child in.」這樣子的做法是不能接受的。