one and the 'same 同一个人；同一事物；就是同一个人/事情

real

同一个人；同一事物；就是同一个人/事情， 有个很地道的表达：one and the same



one and the 'same
   the same person or thing
   同一个人；同一事物:
   It turns out that her aunt and my cousin are one and the same.
   原来她姑妈就是我表姐。


The restaurant's owner and chef are one and the same person. [=the owner is also the chef]
餐厅的老板和厨师是同一个人。 [=老板也是厨师]

......and concluded that 'Mr Howard' and the letter-writer were one and the same.

并得出结论，“霍华德先生”和写信人是同一个人。