Answers to the questions : Q. 1 When do I have to give back you the key? Or When do I have to back the key to you? Or When I have to give the key back to you? More to learn today ☺️ Question No. 2 If ''one'' is a pronoun, then why does the possessive add an apostrophe (one's)? Should it be ''ones'' or ''onese'' as the possessive of ''who'' is not ''who's'' but ''whose''? Answer: No. It's not like all that. There are exceptions that you have to follow: I told him my name and he told me his. I told her my name and he told me hers. But in the case of ' one ’ you have to follow ' one's ’, such as One should do one's duty. He should do his duty. Similarly who's can be the connotations of who has, who is, who was, Umer is the boy who wants to study English. Umer is the boy whose teacher is Sir Masood. Umer is the boy whom I teach English. ' Once ' i...