租客每个月把钱交给银行。

1.你爸爸妈妈搬家了吗？- 在中国，这是一个书面的约定。第一放爸爸这个词放第一爸爸，第二放妈妈放第二的词。
2.租客每个月把钱交给银行。
把钱交给-把钱 I am still confused about this construction? any other examples?

3.为什么中国人不需要报税 （declare income and pay taxes) 一个人说“因为我们买东西的时候已经交了税了。”
交了税了- I am confused about this 了 construction

“了” means that you have done something. for example ,我吃了晚饭了，means that you had dinner. sometimes ,you can use the character "过" instead . for example , “我吃了晚饭了”=“我吃过晚饭了” 

商品的价格包含税 - does China only have a consumption based tax (no income tax) ?