Hi, I have the following questions. I hope I can get some help. Thanks.<br/><br/>1) "Who give you the book?" or "Who gave you the book?"<br/><br/>2) "Who won the contest?" or "Who win the contest?"<br/><br/>3) "While she was in London, she always walked to school." or "While she was in London, she always walk to school."<br/><br/>4) "If I know it I would not have done it." or "If I knew it I would not have done it."<br/><br/>5) "I sat on that chair before" or "I seated on that chair before"<br/><br/>6) "You know it didn't you?" or "You knew it, didn't you?"<br/><br/>7) "She give it to you, didn't she?" or "She gave it to you, didn't she?"