The Prepositions Theory is an important aspect of Russian grammar that helps students understand how prepositions function in the language. Prepositions are words that establish relationships between different parts of a sentence, such as time, place, manner, or purpose. In Russian, prepositions are used to indicate spatial relationships, possession, direction, and other concepts.

The Prepositions Theory teaches students about the different categories of prepositions, such as prepositions of place, time, and manner. It also explains how prepositions can change their forms depending on the case or gender of the noun they are referring to. For example, the preposition “в” (in, at) changes to “во” when used before certain words beginning with certain letters.

Additionally, the theory teaches students about the different cases that prepositions require. For example, the preposition “о” (about) requires the prepositional case, while the preposition “за” (behind) requires the accusative case.

By studying the Prepositions Theory, students can gain a deeper understanding of how prepositions function in Russian and improve their overall grammar skills.