In this study, particles were evaluated according to the forms of their connection with case suffixes and their semantic properties. While evaluating, etymology of postpositions and functional properties of case suffixes were emphasized. The particles which were derived from nouns or verbs had to have some changes in the historical development of language. Case suffixes used before particles have also changed during this alteration. The changes in semantic features of the verb or noun from which the particle was derived and the fact that usage properties of particles taken from other languages spread over Turkish language have caused differences in case preferences. On thecontrary, particles used in the old periods of Turkish language and replaced with particles having a foreign etymon in time maintain their usage properties in new particles. Today, it is a general opinion that nouns are connected to particles by means of “nominative, genitive, dative, ablative, and instrumental cases”. Because the first products of old Turkish were examined according to this classification, it was thought that most particles formed a group of particles by being used with nominatives. However, most nominative nouns used before particles in old Turkish have an undetermined accusative case. In this study, it was tried to determine why and how postpositions require a nominative case before themselves.