when后面跟什么时态

问题描述:

when后面跟什么时态

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...