What is "comitative case"

n. (context grammar English) Noun case used to denote companionship. In English, this is usually expressed by the prepositional phrase '''in company with''', '''together with''' or '''with''', as in "with the house." Languages that use the comitative case include Estonian, Finnish, Hungarian, Inari Sami, Northern Sami, Skolt Sami, and Quechua. It is also found in many Australian Aboriginal languages, where it is commonly used to form names of places and languages.

The comitative case (abbreviated ) is a grammatical case that denotes accompaniment. In English, the preposition "with," in the sense of "in company with" or "together with," plays a substantially similar role (other uses of "with," like in the meaning of "using" or "by means of" (I cut bread with a knife), correspond to the instrumental case or related cases).