没有he have no finished his homework之说,这样说是不符合语法的.可以说he have not finished his homework.he didn't finish his homework是he doesn't finish his homework的过去式.he didn't finish his homework表示在以前发生过的对话时说明的那个时候他还没做完作业.he doesn't finish his homework现在（说话当时）还没完成作业.