Compound numerals governed by the final word

In Russian, compound cardinal numerals follow a specific syntax when in the Nominative or Accusative case. The noun's form is governed by the final word's rules:

• Ends in 1 (один/одна/одно/одни): The final word (один/одна/одно/одни) agrees with the noun in gender, case, and number. In the Nominative, the noun is in the Nominative Singular. In the Accusative, it takes the Accusative Singular (e.g., двадцать одну машину [twenty-one cars]). For animate masculine nouns in the Accusative, both the final numeral and the noun obey animacy rules and take the Genitive form (e.g., вижу двадцать одного студента [I see twenty-one students]). If the noun is a 'plural-only' noun (like сутки [days]), use the plural form одни (e.g., двадцать одни сутки [twenty-one days]).
• Ends in 2, 3, 4 (два/две/три/четыре): The noun is in the Genitive Singular. This rule applies in the Accusative even for animate nouns. The strict modern norm is to use the inanimate-looking form (e.g., вижу двадцать два студента [I see twenty-two students]), while the animate variant (e.g., вижу двадцать двух студентов [I see twenty-two students]) is considered obsolescent or incorrect. Exceptions: Masculine and neuter substantivized adjectives (nouns derived from adjectives, like рабочий [worker] or животное [animal]) take the Genitive Plural (e.g., двадцать два рабочих [twenty-two workers], тридцать три животных [thirty-three animals]), while feminine substantivized adjectives (like столовая [cafeteria]) can take the Nominative Plural (e.g., двадцать две столовые [twenty-two cafeterias]). Note that compound numerals ending in 2, 3, or 4 cannot be used with plural-only nouns (pluralia tantum) like сутки [days]. To resolve this, either replace the noun with a countable synonym (e.g., двадцать два дня [twenty-two days]) or rephrase the sentence to use an oblique case where quantitative numerals are allowed (e.g., в течение двадцати двух суток [during twenty-two days]).
• Ends in 5–9, 0, or 11–19: The noun is in the Genitive Plural. In the Accusative case, the numeral form is identical to the Nominative, regardless of animacy (e.g., вижу двадцать пять студентов [I see twenty-five students]).

Adjective Agreement: When an adjective is between the numeral and the noun:

• For numbers ending in 1, the adjective simply agrees with the noun in gender, number, and case (e.g., двадцать один новый стол [twenty-one new tables], двадцать одну новую машину [twenty-one new cars]).
• For numbers ending in 2, 3, 4 with masculine and neuter nouns, the adjective is in the Genitive Plural (e.g., двадцать два новых стола [twenty-two new tables]).
• For numbers ending in 2, 3, 4 with feminine nouns, the adjective is preferred in the Nominative Plural (e.g., тридцать две новые машины [thirty-two new cars]).
• For numbers ending in 5–9, 0, and 11–19, the adjective is always in the Genitive Plural for all genders.

The 'Teen' Exception: Numbers 11 through 19 always require the Genitive Plural, as they are treated as a single unit.

Important Note: These rules only apply in the Nominative and Accusative. In other cases (Dative, Genitive, etc.), all parts of the numeral decline, and the noun simply agrees with the case of the numeral (see Case in compound numerals).