What's the structure of this word / sentence? 搬进、走出、跑回
The “进” part is called directional complement.


  Rather simply, as we do in English, you can add a directional word to the verb, to describe where the verb is going. The most common words to indicate a direction are:
  
  
  上, up and 下, down &lt;== notice how they kind of look like arrows?
  进, in and 出, out
  过, to cross over
  起, up
  回 to come back.
  到 (to arrive) to
  


So, “搬进” is “move in/into”, “走出” is “walk out (of)”, “跑回” is “run back to”.