Instrumental case is used with the preposition мљжду for location as well as motion.
  Рџчка лежќт мљжду ітими кнќгами. The pen is lying between those books.
  Онђ положќла рџчку мљжду ітими кнќгами. She put the pen between those books.
Some of the prepositions used with the Instrumental case are also used with other case forms. Their meaning depends on the case.
Instrumental vs. Genitive after с: 'with, along with' vs. 'off'
  Ї гулїла по пђрку с мџжем (Inst.). I was strolling in the park with my husband.
  Кнќга, нављрно, упђла со столђ (Gen.). The book probably fell off the table.
Instrumental vs. Accusative after под: location vs. motion
  Кнќга лежќт под столћм (Inst.). The book is under the table.
  Онђ положќла кнќгу под стћл (Acc.). She put the book under the table.