完整的句子是
Harry poter is grown up,and he is no longer a boy wizard but a responsible and mature young man.
由于没有连词and,一个句子中只能出现一个谓语动词,且前后主语一致.
所以直接改为 Harry poter who is grown up is no longer a boy wizard but a responsible and mature young man.= Harry poter ,grown up,is no longer a boy wizard but a responsible and mature young man = Grown up,Harry poter ,is no longer a boy wizard but a responsible and mature young man
定语状语修饰Harry poter,完成式不能作定语.
1.The girl who has passed the exam is my gf.( Right)
2.The girl having passed the exam is my gf.( Wrong )