For teaching Hindi language at the primary stage, the most necessary thing is—

Research in early language acquisition emphasizes that a print-rich environment—with displays, charts, labels, story corners, children's writing on walls, books accessible to children—is the most crucial factor for primary-stage language learning. It provides constant exposure to written language in meaningful contexts, supports incidental learning, and creates motivation to read and write. While teacher knowledge and textbooks help, the immersive print environment is foundational for emergent literacy.