[Teacher] 2013-9-26

什么时候 shenme  shihou - when
e.g.
你什么时候上学？ni shenme shihou shangxue? / When do you go to school?
中秋节是什么时候？zhongqiujie shi shenme shihou? / When is mid-autumn festival?

为什么 weishenme - why