Cases & aspect: the system in 20 min

6 cases: Nom. (who/what — subject), Gen. (whose — absent), Dat. (to whom), Acc. (whom/what), Instr. (with what), Prep. (about what). Each has its question and prepositions. Aspect: perfective (what done? — result, once) vs imperfective (what doing? — process, repeated). This is the key — master these two blocks and 80% of rules follow.

• ●Nom. who? mother | Gen. no whom? mother | Dat. to whom? mother
• ●Acc. whom? mother | Instr. with whom? mother | Prep. about whom? mother
• ●Pfv.: прочитал (finished) | Ipfv.: читал (process)