1that is the mistake that i am complaining (that có thể thay thế cho which)

2 he is the man whom the novel was written by (the man - him )

  he is the man that the novel was written by (that =whom)

3 that is the shop where i bought the radio from( the shop chỉ địa điểm)

4 Mr Cox who saw Ann is the manager( Mr Cox là chủ ngữ nên chuyển who sau chủ ngữ )

6 the woman who is a milionaire travels everywhere by private plane