We are going to buy a birthday cake for Miss Wang.如何改写成一般疑问句?

Are you going to buy a birthday cake for Miss Wang?那写成肯定句与否定句呢？是不是？Yes,We are/No,we aren't?嗯，是肯定回答和否定回答。Mike is going to Shanghai this week.改写成一般疑问句？？是Is Mike going to Shanghai this week?吗是的。