The preposition در (“dar”) marks the locative case in Persian. The locative is a grammatical case that typically indicates place. In Persian, it is also used to indicate time and consequently, it can be viewed as a case that marks a location in place or time. In Latin, the ablative and the accusative cases are used to specify time. Persian makes a clear distinction and uses the ablative for “motion from” (i.e. source), the dative for “motion to” (i.e. target) and the locative for the exact location.

Marking the locative case in Persian is similar to languages like Turkish and Japanese in that a single adposition or particle is used to indicate time or place rather than an inflected form. This is different from languages like English that lack a unique word to indicate place or time.