Purpose

By the end of this lesson, you will be able to correctly apply the full case-government rules for Russian numbers, building on the preview from Part 1, Lesson 2.

Lesson Explanation

This lesson completes the number/case interaction previewed in Part 1, Lesson 2, now that the full case system (Parts 2-3) has been covered.

Recall the core rule: один (one) agrees like an adjective; два, три, четыре require the genitive SINGULAR; пять and above require the genitive PLURAL (Part 3, Lesson 1). This rule holds regardless of the CASE of the number phrase as a whole — but the number itself also declines when the whole phrase isn’t in the nominative/accusative, adding a genuinely important further layer.

When the entire number-plus-noun phrase is governed by another case (for example, after a preposition requiring the dative or instrumental), BOTH the number and the noun shift into that case together, and the special “два/три/четыре + genitive singular” rule genuinely no longer applies — the noun instead simply matches the number’s case like a normal adjective-noun pair: с двумя студентами (with two students — instrumental, both number and noun in the instrumental, not the genitive singular that “два” would otherwise require in the nominative/accusative).

A genuinely important, related detail: compound numbers (21, 32, etc.) take their case-government rule from the LAST digit only, not the whole number: двадцать один студент (21 students — “один” governs, so nominative singular, like “one student,” not genitive plural) versus двадцать два студента (22 students — “два” governs, genitive singular). This last-digit rule is genuinely essential for correctly pairing any number above 20 with its noun.

Practice Questions