Q: Why do some names end in Ji or Sahib?
A: Ji is not a part of the name, it is usually used as a sign of respect to elder people or whomever you want to denote with respect. Ji is used after the names of Sikh Gurus as a sign of respect. For example: Guru Gobind Singh Ji.
Sahib is another word for respect but it is used to denote someone who has higher status. For example: Guru Granth Sahib Ji. Sahib is also used as a form of respect to people at higher military, political and work related posts.