he asked Tom whether he had finished his homework这是对的

he asked Tom whether he had finished his homework这是对的 He asked Tom if he had finished homework．对奥妙 — He asked Tom, "Have you finished your homework?" I waited until he had finished his homework.请问这句的过去完成时为何是用在f He had finished his homework before he watched TV Tom went back home after he finished all his homework tom has finished his homework doesn't he Tom went home after he finished his homework. He had finished his homework already.(改为否定句) I __ he had finished his homework at this time he finished his homework _____. He___until he finished his homework?