Many Russian exams require students to explain their reasoning, not just provide a correct answer.
It bridges the gap between simple translation and understanding nuance.
ГДЗ по русскому языку за 5 класс, решебник и ответы онлайн
Many Russian educational sites offer "Reshebniks" (solution books) that include the detailed word-level commentary you are looking for, focusing on difficult themes like case usage and verb aspects. Why Word Explanations Matter