I was told if I made the transfer from chequing account to Mortgage account myself, part of will go to interest, part of will go to principal. However, If I let them do it, the whole transfer will go to principal. 我怎么理解不了呢?所发生的bi-weekly利息不是由bi-weekly出吗?lump-sum payment为什么要付利息呢?谢谢