Problem: Of one thing Mark was sure. Harry knew much less than *he* did.

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

Answer: yes

Problem: John hired Bill to take care of *him* .

Do "him" and "John" mean the same thing?

Answer: yes

Problem: Alice looked for her friend Jade in the crowd. Since *she* always has good luck, Alice spotted her quickly.

Do "she" and "Alice" mean the same thing?

Answer:
yes