除了现在进行时,可以跟任何时态.
1.When do the birds fly to the south every year?
鸟儿每年何时飞往南方?一般现在时.
2.When will you go to America?
你何时要去美国?将来时.
3.When did you come back to China?
你什么时候回到中国来的?过去时.