Where do you think he comes from与Do you think where he comes from的区别与相关语法

Where do you think he comes from?(do you think 是插入语,what引导的特殊疑问句）Do you think where he comes from?是一个错误的语法!意思就表达不通.Do you know where he comes from?这还差不多.而且告诉你吧Do...