Problem: James asked Robert for a favor but *he* refused.

Do "he" and "Robert" mean the same thing?

Answer: yes

Problem: There is a pillar between me and the stage , and I can't see around *it* .

Do "it" and "the stage" mean the same thing?

Answer: no

Problem: I asked Dave to get me my sweater from the other side of the yacht . While he was gone, I rested my arm on the rail over there and suddenly *it* gave way.

Do "it" and "arm" mean the same thing?

Answer:
no